When was Dupont founded?

E. I. du Pont de Nemours and Company, commonly referred to as DuPont (), is an American conglomerate that was founded in July 1802 in Wilmington, Delaware, as a gunpowder mill by French-American chemist and industrialist Éleuthère Irénée du Pont.

DuPont

In the 20th century, DuPont developed many polymers such as Vespel, neoprene, nylon, Corian, Teflon, Mylar, Kapton, Kevlar, Zemdrain, M5 fiber, Nomex, Tyvek, Sorona, Corfam, and Lycra. DuPont developed Freon (chlorofluorocarbons) for the refrigerant industry, and later other refrigerants. It also developed synthetic pigments and paints including ChromaFlair.

In 2014, DuPont was the world's fourth-largest chemical company based on market capitalization and eighth-largest based on revenue. On August 31, 2017, it merged with the Dow Chemical Company to create DowDuPont, the world's largest chemical company in terms of sales, of which DuPont is now a subsidiary. Its stock price is a component of the Dow Jones Industrial Average.

DuPont was founded in 1802 by Éleuthère Irénée du Pont, using capital raised in France and gunpowder machinery imported from France. He started the company at the Eleutherian Mills, on the Brandywine Creek, near Wilmington, Delaware, two years after du Pont and his family left France to escape the French Revolution and religious persecution against Huguenot Protestants. The company began as a manufacturer of gunpowder, as du Pont noticed that the industry in North America was lagging behind Europe. The company grew quickly, and by the mid-19th century had become the largest supplier of gunpowder to the United States military, supplying half the powder used by the Union Army during the American Civil War. The Eleutherian Mills site is now a museum and a National Historic Landmark.

DuPont continued to expand, moving into the production of dynamite and smokeless powder. In 1902, DuPont's president, Eugene du Pont, died, and the surviving partners sold the company to three great-grandsons of the original founder. Charles Lee Reese was appointed as director and the company began centralizing their research departments. The company subsequently purchased several smaller chemical companies; in 1912 these actions generated government scrutiny under the Sherman Antitrust Act. The courts declared that the company's dominance of the explosives business constituted a monopoly and ordered divestment. The court ruling resulted in the creation of the Hercules Powder Company (later Hercules Inc. and now part of Ashland Inc.) and the Atlas Powder Company (purchased by Imperial Chemical Industries (ICI) and now part of AkzoNobel). At the time of divestment, DuPont retained the single-base nitrocellulose powders, while Hercules held the double-base powders combining nitrocellulose and nitroglycerine. DuPont subsequently developed the Improved Military Rifle (IMR) line of smokeless powders.

In 1910, DuPont published a brochure entitled "Farming with Dynamite". The pamphlet was instructional, outlining the benefits to using their dynamite products on stumps and various other obstacles that would be easier to remove with dynamite as opposed to other more conventional and inefficient means.

DuPont also established two of the first industrial laboratories in the United States, where they began the work on cellulose chemistry, lacquers and other non-explosive products. DuPont Central Research was established at the DuPont Experimental Station, across the Brandywine Creek from the original powder mills.

In 1914, Pierre S. du Pont invested in the fledgling automobile industry, buying stock in General Motors (GM). The following year he was invited to be on GM's board of directors and would eventually be appointed the company's chairman. The DuPont company would assist the struggling automobile company further with a $25 million purchase of GM stock. In 1920, Pierre S. du Pont was elected president of General Motors. Under du Pont's guidance, GM became the number one automobile company in the world. However, in 1957, because of DuPont's influence within GM, further action under the Clayton Antitrust Act forced DuPont to divest its shares of General Motors.

In the 1920s, DuPont continued its emphasis on materials science, hiring Wallace Carothers to work on polymers in 1928. Carothers invented neoprene, a synthetic rubber; the first polyester superpolymer; and, in 1935, nylon. The invention of Teflon followed a few years later. DuPont introduced phenothiazine as an insecticide in 1935.

DuPont ranked 15th among United States corporations in the value of wartime production contracts. As the inventor and manufacturer of nylon, DuPont helped produce the raw materials for parachutes, powder bags, and tires.

DuPont also played a major role in the Manhattan Project in 1943, designing, building and operating the Hanford plutonium producing plant in Hanford, Washington. In 1950 DuPont also agreed to build the Savannah River Plant in South Carolina as part of the effort to create a hydrogen bomb.

After the war, DuPont continued its emphasis on new materials, developing Mylar, Dacron, Orlon, and Lycra in the 1950s, and Tyvek, Nomex, Qiana, Corfam, and Corian in the 1960s. DuPont materials were critical to the success of the Apollo Project of the United States space program.

DuPont has been the key company behind the development of modern body armor. In the Second World War DuPont's ballistic nylon was used by Britain's Royal Air Force to make flak jackets. With the development of Kevlar in the 1960s, DuPont began tests to see if it could resist a lead bullet. This research would ultimately lead to the bullet-resistant vests that are the mainstay of police and military units in the industrialized world.

In 1981, DuPont acquired Conoco Inc., a major American oil and gas producing company, which gave it a secure source of petroleum feedstocks needed for the manufacturing of many of its fiber and plastics products. The acquisition, which made DuPont one of the top ten U.S.-based petroleum and natural gas producers and refiners, came about after a bidding war with the giant distillery Seagram Company Ltd.. Seagram became DuPont's largest single shareholder, with four seats on the board of directors. On April 6, 1995, after being approached by Seagram Chief Executive Officer Edgar Bronfman Jr., DuPont announced a deal in which the company would buy back all the shares owned by Seagram.

In 1999, DuPont sold all of its shares of Conoco, which merged with Phillips Petroleum Company. DuPont acquired the Pioneer Hi-Bred agricultural seed company.

DuPont describes itself as a global science company that employs more than 60,000 people worldwide and has a diverse array of product offerings. The company ranks 86th in the Fortune 500 on the strength of nearly $36 billion in revenues, $4.848 billion in profits in 2013. In April 2014, "Forbes" ranked DuPont 171st on its Global 2000, the listing of the world's top public companies.

DuPont businesses are organized into the following five categories, known as marketing "platforms": Electronic and Communication Technologies, Performance Materials, Coatings and Color Technologies, Safety and Protection, and Agriculture and Nutrition.
The agriculture division, DuPont Pioneer, makes and sells hybrid seed and genetically modified seed, some of which produces genetically modified food. Genes engineered into their products include LibertyLink, which provides resistance to Bayer's Ignite Herbicide/Liberty herbicides; the Herculex I Insect Protection gene, which provides protection against various insects; the Herculex RW insect protection trait, which provides protection against other insects; the YieldGard Corn Borer gene, which provides resistance to another set of insects; and the Roundup Ready Corn 2 trait that provides crop resistance against glyphosate herbicides.

In 2010, DuPont Pioneer received approval to start marketing Plenish soybeans, which contain "the highest oleic acid content of any commercial soybean product, at more than 75 percent. Plenish provides a product with no trans fat, 20 percent less saturated fat than regular soybean oil, and more stable oil with greater flexibility in food and industrial applications." Plenish is genetically engineered to "block the formation of enzymes that continue the cascade downstream from oleic acid (that produces saturated fats), resulting in an accumulation of the desirable monounsaturated acid."

In October 2001, the company sold its pharmaceutical business to Bristol Myers Squibb for $7.798 billion.

In 2002, the company sold the Clysar(R) business to Bemis Company for $143 million.

In 2004, the company sold its textiles business, which included some of its best-known brands such as Lycra (Spandex), Dacron polyester, Orlon acrylic, Antron nylon and Thermolite, to Koch Industries.

In 2011, DuPont was the largest producer of titanium dioxide in the world, primarily provided as a white pigment used in the paper industry.

DuPont has 150 research and development facilities located in China, Brazil, India, Germany, and Switzerland, with an average investment of $2 billion annually in a diverse range of technologies for many markets including agriculture, genetic traits, biofuels, automotive, construction, electronics, chemicals, and industrial materials. DuPont employs more than 10,000 scientists and engineers around the world.

On January 9, 2011, DuPont announced that it had reached an agreement to buy Danish company Danisco for US$6.3 billion. On May 16, 2011, DuPont announced that its tender offer for Danisco had been successful and that it would proceed to redeem the remaining shares and delist the company.

On May 1, 2012, DuPont announced that it had acquired from Bunge full ownership of the Solae joint venture, a soy-based ingredients company. DuPont previously owned 72 percent of the joint venture while Bunge owned the remaining 28 percent.

In February 2013, DuPont Performance Coatings was sold to the Carlyle Group and rebranded as Axalta Coating Systems.

In October 2015, DuPont sold the Neoprene chloroprene rubber business to Denka Performance Elastomers, a joint venture of Denka and Mitsui.

In October 2013, DuPont announced that it was planning to spin off its Performance Chemicals business into a new publicly traded company in mid-2015. The company filed its initial Form 10 with the SEC in December 2014 and announced that the new company would be called The Chemours Company. The spin-off to DuPont shareholders was completed on July 1, 2015, and Chemours stock began trading on the New York Stock Exchange on the same date.

DuPont will focus on production of GMO seeds, materials for solar panels, and alternatives to fossil fuels. Chemours becomes responsible for the cleanup of 171 former DuPont sites, which DuPont says will cost between $295 million and $945 million.

On December 11, 2015, DuPont announced that it would merge with the Dow Chemical Company, in an all-stock deal. The combined company, which will be known as DowDuPont, will have an estimated value of $130 billion, be equally held by the shareholders of both companies, and maintain their headquarters in Delaware and Michigan, respectively. Within two years of the merger's closure, expected in the first quarter of 2017 and subject to regulatory approval, DowDuPont will be split into three separate public companies, focusing on the agricultural chemicals, materials science, and specialty product industries. Commentators have questioned the economic viability of this plan because, of the three companies, only the specialty products industry has prospects for high growth. The outlook on the profitability of the other two proposed companies has been questioned due to reduced crop prices and lower margins on plastics such as polyethylene. They have also noted that the deal is likely to face antitrust scrutiny in several countries. This eventually became the case, with two delays taking place due to regulatory approvals. The merger closed on August 31, 2017.

The company's corporate headquarters are located in Wilmington, Delaware. The company's manufacturing, processing, marketing, and research and development facilities, as well as regional purchasing offices and distribution centers are located throughout the world. Major manufacturing sites include the Spruance plant near Richmond, Virginia, (currently the company's largest plant), the Washington Works site in Washington, West Virginia, the Mobile Manufacturing Center (MMC) in Axis, Alabama, the Bayport plant near Houston, Texas, the Mechelen site in Belgium, and the Changshu site in China. Other locations include the Yerkes Plant on the Niagara River at Tonawanda, New York, the Sabine River Works Plant in Orange, Texas, and the Parlin Site in Sayreville, New Jersey. The facilities in Vadodara, Gujarat and Hyderabad, Telangana in India constitute the DuPont Services Center and DuPont Knowledge Center respectively.On October 5, 2015, DuPont announced that Ellen Kullman would retire as chair and CEO on October 16, 2015. Breen was appointed CEO in November 2015 replacing Kullman.

In the 1990s, DuPont was a founding member of the World Business Council for Sustainable Development with then DuPont CEO Chad Holliday as chairman of the WBCSD from 2000 to 2001. The organization has developed guidelines for measuring sustainability cited by the Natural Resources Defense Council and the Environmental Defense Fund, and its Vision 2050 blueprint for slowing and reversing environmental damage has been highlighted by The Guardian.

In 2005, "BusinessWeek" magazine, in conjunction with the Climate Group, ranked DuPont as the best-practice leader in cutting their carbon gas emissions. DuPont reduced its greenhouse gas emissions by more than 65 percent from the 1990 levels while using 7 percent less energy and producing 30 percent more product.

In May 2007 the $2.1 million DuPont Nature Center at Mispillion Harbor Reserve, a wildlife observatory and interpretive center on the Delaware Bay near Milford, Delaware was opened to enhance the beauty and integrity of the Delaware Estuary. The facility will be state-owned and operated by the Delaware Department of Natural Resources and Environmental Control (DNREC).

In 2010, researchers at the Political Economy Research Institute of the University of Massachusetts Amherst ranked DuPont as the fourth-largest corporate source of air pollution in the United States. DuPont released a statement that 2012 total releases and transfers were 13% lower than 2011 levels, and 70% lower than 1987 levels. Data from the EPA's Toxic Release Inventory database included in the Political Economy Research Institute studies likewise show a reduction in DuPont's emissions from 12.4 million pounds of air releases and 22.4 million pounds of toxic incinerator transfers in 2006 to 10.94 million pounds and 22.0 million pounds, respectively, in 2010. Over the same period, the Political Economy Research Institutes Toxic score for DuPont increased from 122,426 to 7,086,303.

One of DuPont's facilities was listed No. 4 on the "Mother Jones" top 20 polluters of 2010, legally discharging over of toxic chemicals into New Jersey and Delaware waterways. In 2016, Carneys Point Township, New Jersey, where the facility is located, initiated a $1.1 billion lawsuit against the corporation, accusing it of divesting an unprofitable company without first remediating the property as required by law.

In 2012 DuPont was named to the Carbon Disclosure Project Global 500 Leadership Index. Inclusion is based on company performance on sustainability metrics, emissions reduction goals, and environmental performance transparency. In 2014 DuPont was the top scoring company in the chemical sector according to CDP, with a score of "A" or "B" in every evaluation area except for supply chain management.

Between 2007 and 2014 there were thirty-four accidents resulting in toxic releases at DuPont plants across the U.S., with no fewer than 8 fatalities. Four employees died of suffocation in a Houston, Texas, accident involving leakage of nearly of methyl mercaptan. As a result, the company became the largest of the 450 businesses placed into the Occupational Safety and Health Administration's "severe violator program" in July 2015. The program was established for companies OSHA says have repeatedly failed to address safety infractions.

DuPont was part of Global Climate Coalition, a group that lobbied against taking action on climate change.

DuPont has been awarded the National Medal of Technology four times: first in 1990, for its invention of "high-performance man-made polymers such as nylon, neoprene rubber, "Teflon" fluorocarbon resin, and a wide spectrum of new fibers, films, and engineering plastics"; the second in 2002 "for policy and technology leadership in the phaseout and replacement of chlorofluorocarbons". DuPont scientist George Levitt was honored with the medal in 1993 for the development of sulfonylurea herbicides. In 1996, DuPont scientist Stephanie Kwolek was recognized for the discovery and development of Kevlar.

On the company's 200th anniversary in 2002, it was presented with the Honor Award by the National Building Museum in recognition of DuPont's "products that directly influence the construction and design process in the building industry."

Pioneer Hi-Bred, a DuPont subsidiary, manufactures genetically modified seeds, other tools, and agricultural technologies used to increase crop yield.

Dupont, along with Frigidaire and General Motors, was a part of a collaborative effort to find a replacement for toxic refrigerants in the 1920s, resulting in the invention of chlorofluorocarbons (CFCs) by Thomas Midgley in 1928. CFCs are ozone-depleting chemicals that were used primarily in aerosol sprays and refrigerants. DuPont was the largest CFC producer in the world with a 25 percent market share in the 1980s, totaling $600 million in annual sales.

In 1974, responding to public concern about the safety of CFCs, DuPont promised to stop production of CFCs should they be proven to be harmful to the ozone layer.

In February 1988, United States Senator Max Baucus, along with two other Senators, wrote to DuPont reminding the company of its pledge. The "Los Angeles Times" reported that the letter was "generally regarded as an embarrassment for DuPont, which prides itself on its reputation as an environmentally conscious company." The company responded with a strongly worded letter that the available evidence did not support a need to dramatically reduce CFC production and calling the proposal "unwarranted and counterproductive".

On March 14 of the same year, scientists from the National Aeronautics and Space Agency announced the results of a study demonstrating a 2.3% decline in mid-latitude ozone levels between 1969 and 1986, along with evidence tying the decline to CFCs in the upper atmosphere. On March 24, DuPont reversed its position, calling the NASA results "important new information" and announcing that it would phase out CFC production. The company further called for worldwide controls on CFC production and for additional countries to ratify the Montreal Protocol. DuPont's change of policy was widely praised by environmentalists. In 2003, DuPont was awarded the National Medal of Technology, recognizing the company as the leader in developing CFC replacements.

DuPont has faced fines from the U.S. Environmental Protection Agency and litigation over releases of the Teflon-processing aid perfluoro-octanoic acid (PFOA, also known as C8) from their works in Washington, West Virginia PFOA-contaminated drinking water led to increased levels of the compound in the bodies of residents who lived in the surrounding area. A court-appointed C8 Science Panel investigated "whether or not there is a probable link between C8 exposure and disease in the community." They eventually concluded that there is a probable link between PFOA and kidney cancer, testicular cancer, thyroid disease, high cholesterol, pre-eclampsia and ulcerative colitis. Water contamination in the Netherlands and links to cancer are also being investigated.

DuPont agreed to sharply reduce its output of PFOA, and was one of eight companies to sign on with the USEPA's 2010/2015 PFOA Stewardship Program. The agreement called for the reduction of "facility emissions and product content of PFOA and related chemicals on a global basis by 95 percent by 2010 and to work toward eliminating emissions and product content of these chemicals by 2015." DuPont phased out PFOA entirely in 2013.

Unlike other persistent organic pollutants, perfluorooctanoic acid persists indefinitely and is completely resistant to bio-degradation, remaining toxic. The only way to reduce levels in the body is by physical elimination rather than degradation. In 2014, the International Agency for Research on Cancer designated PFOA as "possibly carcinogenic" in humans. One Ohio resident was awarded $1.6 million when a jury in 2015 found that her kidney cancer was caused by PFOA in drinking water. In December 2016 two million dollars was awarded when a jury found it caused the plaintiff's testicular cancer and awarded punitive damages in the amount of $10.5 million. This was the third case where a jury found DuPont liable for injuries resulting from exposure to PFOA in drinking water sources. There were 3,500 similar cases awaiting trial c. 2015. According to the co-lead counselor, internal documents revealed during trial showed DuPont had known of a link between PFOA and cancers since 1997. DuPont maintains it has always handled PFOA "reasonably and responsibly" based on the information they, and industry regulators, had available during its use. However, the jury concluded that DuPont did not act to prevent harm or inform the public, despite the information available.

In October 2010 DuPont began marketing a herbicide called Imprelis, for control of certain plants in turf areas. DuPont voluntarily pulled Imprelis from the market in August 2011 before the Environmental Protection Agency (EPA) issued a mandatory stop-sale order on Imprelis after being alerted of numerous reports from golf courses to nurseries that the product was suspected of injuring and, in some cases, killing trees. Norway spruce, white pines and honey locust proved to be among the species of trees that were susceptible.

In 2005, the company pleaded guilty to fixing prices of chemicals and products that used neoprene, a synthetic rubber, resulting in an $84 million fine.

DuPont is widely known for its sponsorship of former four-time NASCAR Sprint Cup Series champion Jeff Gordon and his Hendrick Motorsports No. 24 Chevrolet SS. DuPont sponsored him since he began in Sprint Cup (then Winston Cup) in 1992. DuPont said this about their sponsorship:
Our sponsorship of Jeff Gordon helps keep DuPont brands and products in the public eye. Branding is a key component of the DuPont knowledge intensity strategy for achieving sustainable growth.

The partnership lasted 18 seasons before DuPont was replaced by AARP Drive to End Hunger as the No. 24 team's primary sponsor. DuPont continued as associate sponsor with a 12-race deal, and the deal was extended to 14 races after DuPont sold its performance coatings business, now known as "Axalta Coating Systems", to The Carlyle Group in a deal worth $4.9 billion.

In addition to Gordon, DuPont sponsored Scott Lagasse in the SuperTruck Series presented by Craftsman during the 1995 season (including a one-off ride for Terry Labonte in the Skoal Bandit Copper World Classic, the inaugural Truck race). In the Busch Series, the company sponsored Ricky Craven's RC Racing team in the early 1990s.

DuPont

E. I. du Pont de Nemours and Company, commonly referred to as DuPont (), is an American conglomerate that was founded in July 1802 in Wilmington, Delaware, as a gunpowder mill by French-American chemist and industrialist Éleuthère Irénée du Pont.

In 1910, DuPont published a brochure entitled "Farming with Dynamite". The pamphlet was instructional, outlining the benefits to using their dynamite products on stumps and various other obstacles that would be easier to remove with dynamite as opposed to other more conventional and inefficient means.

DuPont also established two of the first industrial laboratories in the United States, where they began the work on cellulose chemistry, lacquers and other non-explosive products. DuPont Central Research was established at the DuPont Experimental Station, across the Brandywine Creek from the original powder mills.

DuPont ranked 15th among United States corporations in the value of wartime production contracts. As the inventor and manufacturer of nylon, DuPont helped produce the raw materials for parachutes, powder bags, and tires.

DuPont also played a major role in the Manhattan Project in 1943, designing, building and operating the Hanford plutonium producing plant in Hanford, Washington. In 1950 DuPont also agreed to build the Savannah River Plant in South Carolina as part of the effort to create a hydrogen bomb.

After the war, DuPont continued its emphasis on new materials, developing Mylar, Dacron, Orlon, and Lycra in the 1950s, and Tyvek, Nomex, Qiana, Corfam, and Corian in the 1960s. DuPont materials were critical to the success of the Apollo Project of the United States space program.

In 1999, DuPont sold all of its shares of Conoco, which merged with Phillips Petroleum Company. DuPont acquired the Pioneer Hi-Bred agricultural seed company.

In October 2001, the company sold its pharmaceutical business to Bristol Myers Squibb for $7.798 billion.

In 2002, the company sold the Clysar(R) business to Bemis Company for $143 million.

In 2004, the company sold its textiles business, which included some of its best-known brands such as Lycra (Spandex), Dacron polyester, Orlon acrylic, Antron nylon and Thermolite, to Koch Industries.

In 2011, DuPont was the largest producer of titanium dioxide in the world, primarily provided as a white pigment used in the paper industry.

On January 9, 2011, DuPont announced that it had reached an agreement to buy Danish company Danisco for US$6.3 billion. On May 16, 2011, DuPont announced that its tender offer for Danisco had been successful and that it would proceed to redeem the remaining shares and delist the company.

On May 1, 2012, DuPont announced that it had acquired from Bunge full ownership of the Solae joint venture, a soy-based ingredients company. DuPont previously owned 72 percent of the joint venture while Bunge owned the remaining 28 percent.

In February 2013, DuPont Performance Coatings was sold to the Carlyle Group and rebranded as Axalta Coating Systems.

In October 2015, DuPont sold the Neoprene chloroprene rubber business to Denka Performance Elastomers, a joint venture of Denka and Mitsui.

DuPont will focus on production of GMO seeds, materials for solar panels, and alternatives to fossil fuels. Chemours becomes responsible for the cleanup of 171 former DuPont sites, which DuPont says will cost between $295 million and $945 million.

In 2005, "BusinessWeek" magazine, in conjunction with the Climate Group, ranked DuPont as the best-practice leader in cutting their carbon gas emissions. DuPont reduced its greenhouse gas emissions by more than 65 percent from the 1990 levels while using 7 percent less energy and producing 30 percent more product.

DuPont was part of Global Climate Coalition, a group that lobbied against taking action on climate change.

On the company's 200th anniversary in 2002, it was presented with the Honor Award by the National Building Museum in recognition of DuPont's "products that directly influence the construction and design process in the building industry."

Pioneer Hi-Bred, a DuPont subsidiary, manufactures genetically modified seeds, other tools, and agricultural technologies used to increase crop yield.

In 1974, responding to public concern about the safety of CFCs, DuPont promised to stop production of CFCs should they be proven to be harmful to the ozone layer.

In 2005, the company pleaded guilty to fixing prices of chemicals and products that used neoprene, a synthetic rubber, resulting in an $84 million fine.


What is the fastest swimming animal?

The fastest land animal is the cheetah, which has a recorded speed of. The peregrine falcon is the fastest bird and the fastest member of the animal kingdom with a diving speed of. The fastest animal in the sea is the black marlin, which has a recorded speed of.

Fastest animals

This is a list of the fastest animals in the world, grouped by types of animal.

While comparing between various classes of animals, a different unit is used, body length per second for organisms. The fastest organism on earth, relative to body length, is the South Californian mite "Paratarsotomus macropalpis", which has a speed of 322 body lengths per second. The equivalent speed for a human running as fast as this mite would be. This is far in excess of the previous record holder, the Australian tiger beetle, "Cicindela eburneola", the fastest insect in the world relative to body size, which has been recorded at or 171 body lengths per second. The cheetah, the fastest land mammal, scores at only 16 body lengths per second while Anna's hummingbird has the highest known length-specific velocity attained by any vertebrate


How large is a cat's brain?

The brain of the domesticated cat is about long, and weighs. If a typical cat is taken to be long with a weight of, then the brain would be at 0.91% of its total body mass, compared to 2.33% of total body mass in the average human. Within the encephalization quotient proposed by Jerison in 1973, values above 1 are classified big brained, while values lower than 1 are small brained. The domestic cat is attributed a value of between 1–1.71 relative to human value that is 7.44–7.8. The largest brains in the Felidae family are those of the tigers in Java and Bali, of which the largest relative brain size within the "panthera" is the "tigris". It is debated whether there exists a causal relationship between brain size and intelligence in vertebrates. Correlations have been shown between these factors in a number of experiments. However, correlation does not imply causation. Most experiments involving the relevance of brain size to intelligence hinge on the assumption that complex behavior requires a complex (and therefore intelligent) brain; however, this connection has not been consistently demonstrated.

Cat intelligence

Cat intelligence is the capacity of the domesticated cat to solve problems and adapt to its environment. Researchers have also shown feline intelligence to include the ability to acquire new behavior that applies previously learned knowledge to new situations, communicating needs and desires within a social group, and responding to training cues.

The surface area of a cat's cerebral cortex is approximately whereas the human brain has a surface area of about. Furthermore, a theoretical cat weighing has a cerebellum weighing, 0.17% of the total weight.

According to researchers at Tufts University School of Veterinary Medicine, the physical structure of the brains of humans and cats is very similar. The human brain and the cat brain both have cerebral cortices with similar lobes.

The number of cortical neurons contained in the brain of the cat is reported to be 763 million. Area 17 of the visual cortex was found to contain about 51,400 neurons per mm. Area 17 is the primary visual cortex.

Both human and feline brains are gyrencephalic, i.e. they have a surface folding.

Analyses of cat brains have shown they are divided into many areas with specialized tasks that are extremely interconnected and share sensory information in a kind of hub-and-spoke network, with a large number of specialized hubs and many alternative paths between them. This exchange of sensory information allows the brain to construct a complex perception of the real world and to react to and manipulate its environment.

The thalamus of the cat includes a hypothalamus, an epithalamus, a lateral geniculate nucleus, and additional secondary nuclear structures.

The domestic cat brain also contains the hippocampus, amygdala, frontal lobes (which comprise 3 to 3.5% of the total brain in cats compared to about 25% in humans), corpus callosum, anterior commissure, pineal gland, caudate nucleus, septal nuclei and midbrain.

Grouse "et al." 1979 ascertained the neuroplasticity of kittens' brains, with respect to control of visual stimulus correlated with changes in RNA structures. In a later study, it was found that cats possess visual-recognition memory, and have flexibility of cerebral encoding from visual information.

A cognitive support diet for felines is a food that is formulated to improve mental processes like attention, short and long-term memory, learning, and problem solving. Claims for cognitive support appear on a number of kitten formulations to help with brain development, as well as diets aimed at seniors to help prevent cognitive disorders. These diets typically focus on supplying Omega-3 fatty acids, omega-6 fatty acids, taurine, vitamins, and other supporting supplements that have positive effects on cognition.

The omega-3 fatty acids are a key nutrient in cognition for felines. They are essential for felines as they cannot be synthesized naturally and must be obtained from the diet. Omega-3 fatty acids that support brain development and function are alpha-linolenic acid, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Fish oils, fish and other marine sources provide a very rich source of DHA and EPA. Alpha-linolenic acid can be acquired from oils and seeds.

Omega-6 fatty acids are also needed in feline cognition diets. The important omega-6 fatty acid that plays a role in brain support and cognition is arachidonic acid. Arachidonic acid or AA is found in animal sources such as meat and eggs. AA is required in cat diets, as felines convert insignificant amounts of it from linoleic acid due to the limited delta-6 desaturase. Like DHA, arachidonic acid is often found in the brain tissues of cats and seems to have a supporting role in brain function. In a 2000 study completed by Contreras "et al.", it was found that DHA and AA made up 20% of the fatty acids in the mammalian brain. Arachidonic acid makes up high amounts in the membrane of most cells and has many pro-inflammatory actions.

Taurine is an amino acid, which is essential in cat diets due to their low capacity to synthesize it. Because taurine has the ability to cross the blood–brain barrier in the brain, it has been found to have a role in many neurological functions, especially in the visual development. Without taurine, felines can have an abnormal morphology in the cerebellum and visual cortex. When cats were fed a diet deficient in taurine, this leads to a decrease in the concentration of taurine in the retina of the eye. This results in deterioration of the photoreceptors, followed by complete blindness.

Choline is a water-soluble nutrient that prevents and improves epilepsy and cognitive disorders. Supplementation is part of therapy for cats with seizures and Feline cognitive dysfunction, despite this treatment being mostly based on anecdotal evidence and research done on dogs. It is the precursor to nerve chemicals like dopamine and acetylcholine, making it important for proper functioning of the nervous system.

Intelligence through behavioural observation is defined as a composite of skills and abilities.
The WAIS test is a measure of intelligence in adult "homo sapiens". The test scores on four criteria: verbal comprehension, perceptual organization, working memory and processing speed. In a comparative evaluation from WAIS criteria, cats are generally fair in intelligence.

In controlled experiments, cats showed that they had fully developed concepts of object permanence, meaning that sensorimotor intelligence is completely developed in cats. For human infants, tests involving multiple invisible displacements of an object are used to assess the beginning of mental representation in the sixth and last stage of sensorimotor intelligence. The cats' searches on these tasks were consistent with representation of an unsensed object and fully developed sensorimotor intelligence. The working memory for object permanence of the domesticated cat is surmised from experiment as being of 16 hours.

More negative results were obtained in an experiment conducted in 2009 where cats could pull on a string to retrieve a treat under a plastic screen. When presented with one string, cats had no trouble getting the treats, but when presented with multiple strings, some of which were not connected to treats, the cats were unable to consistently choose the correct strings, leading to the conclusion that cats do not understand cause and effect in the same way that humans do.

Cats have complex dreams while sleeping, retaining and recalling long sequences of events while they are asleep, as many other animals do. A dreaming cat will usually have rapid, uncontrolled facial, whisker, paw, and abdominal movements. Occasionally cats have violent nightmares with muffled screams and may suddenly wake up screaming from the nightmare.

Taken as a whole, cats have excellent memories. In experimental conditions, the memory of a cat was demonstrated as having an information-retention or recall, of a duration totalling as much as 10 years. However, relationships with humans, individual differences in intelligence, and age may all affect memory. Cats easily adapt to their current environment because they can adapt their memories of past environments throughout their lives.

The period during which the cat is a kitten is the time when the cat learns and memorizes survival skills, which are acquired through observation of their mothers and playing with other cats. Playing, in fact, constitutes more than fun for a kitten, for it is essential for ranking social order, building hunting skills, and generally exercising for the adult roles.

The first two to seven weeks are a particularly critical time for kittens, for it is during this period that they bond with other cats. It has been suspected that without any human contact during this time, the cat would forever mistrust humans.

Just as in humans, advancing age may affect memory in cats. Some cats may experience a weakening of both learning ability and memory that affects them adversely in ways similar to those occurring in poorly aging humans. A slowing of function is normal, and this includes memory. Aging may affect memory by changing the way their brain stores information and by making it harder to recall stored information. Cats lose brain cells as they age, just as humans do. The older the cat, the more these changes can affect its memory. There have been no studies done on the memories of aging cats, but there is some speculation that, just like people, short-term memory is more affected by aging. In one test of where to find food, cats' short-term memory lasted about 16 hours.

Disease, such as feline cognitive dysfunction (FCD) – a condition similar to Alzheimer's disease in humans – could also affect cat memory. Symptoms of FCD include disorientation, reduced social interaction, sleep disturbances, and loss of house training. FCD causes degenerative changes in the brain that are the source of the functional impairment.

Edward Thorndike conducted some key experiments on cat's learning capacity. In one of Thorndike's experiments, cats were placed in various boxes approximately with a door opened by pulling a weight attached to it. The cats were observed to free themselves from the boxes by "trial and error with accidental success." In one test the cat was shown to have done worse in a later trial than in an earlier one, suggesting that no learning from the previous trials was retained in long-term memory. Therefore, Thorndike considered the cat to have the capacity for learning due to the "law of effect", which states that responses followed by satisfaction (i.e. a reward) become more likely responses to the same stimulus in the future. Thorndike was generally skeptical of the presence of intelligence in cats, criticising sources of the contemporary writing of the sentience of animals as "partiality in deductions from facts and more especially in the choice of facts for investigation."

An experiment was done to identify possible observational learning in kittens. Kittens that were able to observe their mothers performing an experimentally organised act were able to perform the same act sooner than kittens that had observed a non-related adult cat, and sooner than the ones who, being placed in trial and error conditions, observed no other cat performing the act.

Cat intelligence study is mostly from consideration of the domesticated cat. The process of domestication has allowed for closer observation of cat behaviour and in the increased incidence of interspecies communication, and the inherent plasticity of the cat's brain has become apparent as the number of studies in this have increased scientific insight. Changes in the genetic structure of a number of cats have been identified as a consequence of both domestication practises and the activity of breeding, so that the species has undergone genetic evolutionary change due to human selection (although this human selection has been coupled with an initial naturally occurring selective set of cats possessing characteristics desirable for the sharing of human habitation and living in Neolithic urban environments).

Cats' intelligence may have increased during their semi-domestication: urban living may have provided an enriched and stimulating environment requiring novel adaptive behaviours. This scavenging behaviour would only have produced slow changes in evolutionary terms, but such changes would have been comparable to the changes to the brain of early primitive hominids who co-existed with primitive cats (like, for example, Machairodontinae, Megantereon and Homotherium) and adapted to savannah conditions.

Cat's urban living is, however, unlikely to indefinitely improve the animal's intelligence: consider the fossil-based family tree of placental mammals above; the feline line diverged many years previously from the primate line; the cat both feral and domesticated is likely to be maintained in an evolutionary stasis by its niche position in the food web.

Cats are known to be trained to perform as circus animals. An example of this is The Yuri Kuklachev Cat Theatre based in Moscow, the owner of which has been training cats for many years to perform a range of circus-style tricks.

In November 2009, scientists claimed to simulate a cat's brain using a supercomputer containing 24,576 processors. This experiment did not simulate the function of the individual neurons in the brain, nor their synaptic patterns. It was intended to demonstrate that the problem of simulating a biological brain could be scaled to very large supercomputer platforms. However, the approach has been criticised as flawed.

There are a number of reasons for why the cat brain is a goal of computer simulations. Cats are familiar and easily kept animals, so the physiology of cats has been particularly well studied. The physical structures of human brains and cat brains are very similar. Cats, like humans, have binocular vision that gives them depth perception. Moreover, trying to build artificial mammal brains advances the research of both neuroscience and artificial intelligence.

Domestic cats have barbed penises, with about 120–150 one millimeter long backwards-pointing spines. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which is a trigger for ovulation. Lions also have barbed penises. Male felids urinate backwards by curving the tip of the glans penis backward. When male cheetahs urine-mark their territories, they stand one meter away from a tree or rock surface with the tail raised, pointing the penis either horizontally backward or 60° upward.

Penis

A penis (plural "penises" or "penes" ) is the primary sexual organ that male animals use to inseminate sexually receptive mates (usually females and hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do not bear a penis in every animal species, and in those species in which the male does bear a so-called penis, the penes in the various species are not necessarily homologous. For example, the penis of a mammal is at most analogous to the penis of a male insect or barnacle.

The term "penis" applies to many intromittent organs, but not to all; for example the intromittent organ of most cephalopoda is the hectocotylus, a specialised arm, and male spiders use their pedipalps. Even within the Vertebrata there are morphological variants with specific terminology, such as hemipenes.

In most species of animals in which there is an organ that might reasonably be described as a penis, it has no major function other than intromission, or at least conveying the sperm to the female, but in the placental mammals the penis bears the distal part of the urethra, which discharges both urine during urination and semen during copulation.

Most male birds (e.g., roosters and turkeys) have a cloaca (also present on the female), but not a penis. Among bird species with a penis are paleognathes (tinamous and ratites) and Anatidae (ducks, geese and swans). A bird penis is different in structure from mammal penises, being an erectile expansion of the cloacal wall and being erected by lymph, not blood. It is usually partially feathered and in some species features spines and brush-like filaments, and in flaccid state curls up inside the cloaca. The lake duck (also called Argentine blue-bill) has the largest penis in relation to body size of all vertebrates; while usually about half the body size (20 cm), a specimen with a penis 42.5 cm long is documented.

While most male birds have no external genitalia, male waterfowl (Anatidae) have a phallus. Most birds mate with the males balancing on top of the females and touching cloacas in a "cloacal kiss"; this makes forceful insemination very difficult. The phallus that male waterfowl have evolved everts out of their bodies (in a clockwise coil) and aids in inseminating females without their cooperation. The male waterfowl evolution of a phallus to forcefully copulate with females has led to counteradaptations in females in the form of vaginal structures called dead end sacs and clockwise coils. These structures make it harder for males to achieve intromission. The clockwise coils are significant because the male phallus everts out of their body in a counter-clockwise spiral; therefore, a clockwise vaginal structure would impede forceful copulation. Studies have shown that the longer a male's phallus is, the more elaborate the vaginal structures were.

The lake duck is notable for possessing, in relation to body length, the longest penis of all vertebrates; the penis, which is typically coiled up in flaccid state, can reach about the same length as the animal himself when fully erect, but is more commonly about half the bird's length. It is theorized that the remarkable size of their spiny penises with bristled tips may have evolved in response to competitive pressure in these highly promiscuous birds, removing sperm from previous matings in the manner of a bottle brush.

Male and female emus are similar in appearance, although the male's penis can become visible when it defecates.

The male tinamou has a corkscrew shaped penis, similar to those of the ratites and to the hemipenis of some reptiles. Females have a small phallic organ in the cloaca which becomes larger during the breeding season.

As with any other bodily attribute, the length and girth of the penis can be highly variable between mammals of different species. In many mammals, the size of a flaccid penis is smaller than its erect size. In the realm of absolute size, the smallest vertebrate penis belongs to the common shrew (5 mm or 0.2 inches).

A bone called the baculum or "os penis" is present in most mammals but absent in humans, cattle and horses.

In mammals the penis is divided into three parts:The internal structures of the penis consist mainly of cavernous, erectile tissue, which is a collection of blood sinusoids separated by sheets of connective tissue (trabeculae). Some mammals have a lot of erectile tissue relative to connective tissue, for example horses. Because of this a horse's penis can enlarge more than a bull's penis. The urethra is on the ventral side of the body of the penis. As a general rule, a mammal's penis is proportional to its body size, but this varies greatly between specieseven between closely related ones. For example, an adult gorilla's erect penis is about in length; an adult chimpanzee, significantly smaller (in body size) than a gorilla, has a penis size about double that of the gorilla. In comparison, the human penis is larger than that of any other primate, both in proportion to body size and in absolute terms.

The penises of even-toed ungulates are curved in an S-shape when not erect. In bulls, rams and boars, the sigmoid flexure of the penis straightens out during erection.

When mating, the tip of a male pronghorn's penis is often the first part to touch the female pronghorn. The pronghorn's penis is about long, and is shaped like an ice pick. The front of a pronghorn's glans penis is relatively flat, while the back is relatively thick. The male pronghorn usually ejaculates immediately after intromission.

The penis of a dromedary camel is covered by a triangular penile sheath opening backwards, and is about long. The camelmen often aid the male to enter his penis into the female's vulva, though the male is considered able to do it on his own. Copulation time ranges from 7 to 35 minutes, averaging 11–15 minutes.

Bulls have a fibro-elastic penis. Given the small amount of erectile tissue, there is little enlargement after erection. The penis is quite rigid when non-erect, and becomes even more rigid during erection. Protrusion is not affected much by erection, but more by relaxation of the retractor penis muscle and straightening of the sigmoid flexure.

The male genitalia of mouse deer are similar to those of pigs. A boar's penis, which rotates rhythmically during copulation, is about long, and ejaculates about a pint of semen. Wild boars have a roughly egg-sized sack near the opening of the penis, which collects urine and emits a sharp odour. The purpose of this is not fully understood.

A stag's penis forms an S-shaped curve when it is not erect, and is retracted into its sheath by the retractor penis muscle. Some deer species spray urine on their bodies by urinating from an erect penis. One type of scent-marking behavior in elk is known as "thrash-urination, which typically involves palpitation of the erect penis. A male elk's urethra points upward so that urine is sprayed almost at a right angle to the penis. A sambar stag will mark himself by spraying urine directly in the face with a highly mobile penis, which is often erect during its rutting activities. Red deer stags often have erect penises during combat.

Cetaceans' reproductive organs are located inside the body. Male cetaceans (whales, dolphins, and porpoises) have two slits, the genital groove concealing the penis and one further behind for the anus. Cetaceans have fibroelastic penises, similar to those of Artiodactyla. The tapering tip of the cetacean penis is called the "pars intrapraeputialis" or "terminal cone". The blue whale has the largest penis of any organism on the planet, typically measuring. Accurate measurements are difficult to take because its erect length can only be observed during mating, which occurs underwater. The penis on a right whale can be up to – the testes, at up to in length, in diameter, and weighing up to, are also by far the largest of any animal on Earth.
On at least one occasion, a dolphin towed bathers through the water by hooking his erect penis around them. Between male bottlenose dolphins, homosexual behaviour includes rubbing of genitals against each other, which sometimes leads to the males swimming belly to belly, inserting the penis in the other's genital slit and sometimes anus.

Stallions (male horses) have a vascular penis. When non-erect, it is quite flaccid and contained within the prepuce (foreskin, or sheath).

Tapirs have exceptionally long penises relative to their body size. The glans of the Malayan tapir resembles a mushroom, and is similar to the glans of the horse. The penis of the Sumatran rhinoceros contains two lateral lobes and a structure called the "processus glandis".

All members of Carnivora (except hyenas) have a baculum.Canine penises have a structure at the base called the bulbus glandis.

During copulation, the spotted hyena inserts his penis through the female's pseudo-penis instead of directly through the vagina, which is blocked by the false scrotum and testes. Once the female retracts her clitoris, the male enters the female by sliding beneath her, an operation facilitated by the penis's upward angle. The pseudo-penis closely resembles the male hyena's penis, but can be distinguished from the male's genitalia by its greater thickness and more rounded glans. In male spotted hyenas, as well as females, the base of the glans is covered with penile spines.

The male fossa has an unusually long penis and baculum (penis bone), reaching to between his front legs when erect, with an average thickness of. The glans extends about halfway down the shaft and is spiny except at the tip. In comparison, the glans of felids is short and spiny, while that of viverrids is smooth and long. Fossa mating includes a copulatory tie, which may be enforced by the male's spiny penis. This unusually lengthy mating is due to the physical nature of the male's erect penis, which has backwards-pointing spines along most of its length. The male fossa has scent glands near the penis, with the penile glands emitting a strong odor.

The beech marten's penis is larger than the pine marten's, with the bacula of young beech martens often outsizing those of old pine martens.

Raccoons have penis bones which bend at a 90 degree angle at the tip. The extrusibility of a raccoon's penis can be used to distinguish mature males from immature males.

Male walruses possess large penis bones, up to in length, the largest of any land mammal, both in absolute size and relative to body size.

The adult male American mink's penis is long, and is covered by a sheath. The baculum is well-developed, being triangular in cross section and curved at the tip.

Males of Racey's pipistrelle bat have a long, straight penis with a notch between the shaft and the narrow, egg-shaped glans penis. Near the top, the penis is haired, but the base is almost naked. In the baculum (penis bone), the shaft is long and narrow and slightly curved. The length of the penis and baculum distinguish "P. raceyi" from all comparably sized African and Malagasy vespertilionids. "P. endoi", "P. paterculus", and "P. abramus" have more similar bacula, but that of "P. abramus" is more curved, the shaft and the tip are more robust in "P. paterculus", and the proximal (near) end is more robust in "P. endoi". In males, penis length is and baculum length is.

Copulation by male greater short-nosed fruit bats is dorsoventral and the females lick the shaft or the base of the male's penis, but not the glans which has already penetrated the vagina. While the females do this, the penis is not withdrawn and research has shown a positive relationship between length of the time that the penis is licked and the duration of copulation. Post copulation genital grooming has also been observed.

The glans penis of the marsh rice rat is long and robust, averaging long and broad, and the baculum (penis bone) is long. As is characteristic of Sigmodontinae, the marsh rice rat has a complex penis, with the distal (far) end of the baculum ending in three digits. The central digit is notably larger than those at the sides. The outer surface of the penis is mostly covered by small spines, but there is a broad band of nonspinous tissue. The papilla (nipple-like projection) on the dorsal (upper) side of the penis is covered with small spines, a character the marsh rice rat shares only with "Oligoryzomys" and "Oryzomys couesi" among oryzomyines examined. On the urethral process, located in the crater at the end of the penis, a fleshy process (the subapical lobule) is present; it is absent in all other oryzomyines with studied penes except "O. couesi" and "Holochilus brasiliensis". The baculum is deeper than it is wide.

In "Transandinomys talamancae", the outer surface of the penis is mostly covered by small spines, but there is a broad band of nonspinous tissue.

Some features of the accessory glands in the male genital region vary among oryzomyines. In "Transandinomys talamancae", a single pair of preputial glands is present at the penis. As is usual for sigmodontines, there are two pairs of ventral prostate glands and a single pair of anterior and dorsal prostate glands. Part of the end of the vesicular gland is irregularly folded, not smooth as in most oryzomyines.

In Pseudorhyzomys, the baculum (penis bone) displays large protuberances at the sides. In the cartilaginous part of the baculum, the central digit is smaller than those at the sides.

In Drymoreomys, there are three digits at the tip of the penis, of which the central one is the largest. The two lateral digits are not supported by mounds of the baculum (penis bone). There is only one spine on the papilla (nipple-like projection) on the upper side of the penis. On the urethral process, located in the crater at the end of the penis, a fleshy process at the side, the lateral lobule, is present. The preputial glands (glands in front of the genitals) are large. The lack of lateral bacular mounds, presence of a lateral lobule, and size of the preputial glands are all unique traits among the oryzomyines.

In "Thomasomys ucucha" the glans penis is rounded, short, and small and is superficially divided into left and right halves by a trough at the top and a ridge at the bottom. Most of the glans is covered with spines, except for an area near the tip.

The glans penis of a male cape ground squirrel is large with a prominent baculum.

Unlike other squirrel species, red squirrels have long, thin, and narrow penises, without a prominent baculum.

Winkelmann's mouse can easily be distinguished from its close relatives by the shape of its penis, which has a partially corrugated glans.

The foreskin of a capybara is attached to the anus in an unusual way, forming an anogenital invagination.

It has been postulated that the shape of the human penis may have been selected by sperm competition. The shape could have favored displacement of seminal fluids implanted within the female reproductive tract by rival males: the thrusting action which occurs during sexual intercourse can mechanically remove seminal fluid out of the cervix area from a previous mating.

The penile morphology of some types of strepsirrhine primates has provided information about their taxonomy. Male galago species possess very distinctive penile morphology that can be used to classify species. In "O. crassicaudatus," the penis is on average in length and increases in width towards the distal tip. The baculum clearly protrudes from the end. The glans and shaft are covered in single keratinized spines that point towards the body.

The northern greater galago penis is on average in length and width of shaft is even from body to bottom of tip. The baculum is clearly visible at the tip. The glans terminates with a characteristic set of curves which does not occur in any other species. The surface is spined with doubled headed or even tridentate spines pointing towards the body. They are less densely packed than in "Otolemur crassicaudatus". The penis of the ring-tailed lemur is nearly cylindrical in shape and is covered in small spines, as well as having two pairs of larger spines on both sides. Males have a relatively small baculum (penis bone) compared to their size. The scrotum, penis, and prepuce are usually coated with a foul-smelling secretion.

The adult male of each vervet monkey species has a pale blue scrotum and a red penis, and male proboscis monkeys have a red penis with a black scrotum.

Male baboons and squirrel monkeys sometimes gesture with an erect penis as both a warning of impending danger and a threat to predators. Genital display among male squirrel monkeys is an important social signal in relation to group hierarchy; it is derived from sexual behavior but is used for social communication. It involves the animal spreading his thighs and having an erect penis.

The human penis is an external sex organ of male humans. It is a reproductive, intromittent organ that additionally serves as the urinal duct. The main parts are the root of the penis (radix): It is the attached part, consisting of the bulb of penis in the middle and the crus of penis, one on either side of the bulb; the body of the penis (corpus); and the epithelium of the penis consists of the shaft skin, the foreskin, and the preputial mucosa on the inside of the foreskin and covering the glans penis.

The human penis is made up of three columns of tissue: two corpora cavernosa lie next to each other on the dorsal side and one corpus spongiosum lies between them on the ventral side. The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus, lies on the tip of the glans penis. It is a passage both for urine and for the ejaculation of semen.

In males, the expulsion of urine from the body is done through the penis. The urethra drains the bladder through the prostate gland where it is joined by the ejaculatory duct, and then onward to the penis.

An erection is the stiffening and rising of the penis, which occurs during sexual arousal, though it can also happen in non-sexual situations. Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm. A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis.

The most common form of genital alteration is circumcision: removal of part or all of the foreskin for various cultural, religious, and more rarely medical reasons. There is controversy surrounding circumcision.

, a systematic review of 15,521 men, and the best research to date on the topic, as the subjects were measured by health professionals, rather than self-measured, has concluded that the average length of an erect human penis is 13.12 cm (5.17 inches) long, while the average circumference of an erect human penis is 11.66 cm (4.59 inches).

Most marsupials, except for the two largest species of kangaroos and marsupial moles (assuming the latter are true marsupials), have a bifurcated penis, separated into two columns, so that the penis has two ends corresponding to the females' two vaginas.

Monotremes and marsupial moles are the only mammals in which the penis is located inside the cloaca.

Male echidnas have a four-headed penis. During mating, the heads on one side "shut down" and do not grow in size; the other two are used to release semen into the female's two-branched reproductive tract. The heads used are swapped each time the mammal copulates. When not in use, the penis is retracted inside a preputial sac in the cloaca. The male echidna's penis is long when erect, and its shaft is covered with penile spines. The penis is nearly a quarter of his body length when erect. Each side of the bilaterally symmetrical, rosette-like, four-headed penis [similar to that of reptiles and in length] is used alternately, with the other half being shut down between ejaculations.

The penis of the bush hyrax is complex and distinct from that of the other hyrax genera. It has a short, thin appendage within a cup-like glans penis and measures greater than when erect. Additionally, it has been observed that the bush hyrax also has a greater distance between the anus and preputial opening in comparison to other hyraxes.

An adult elephant has the largest penis of any land animal. An elephant's penis can reach a length of and a diameter of at the base. It is S-shaped when fully erect and has a Y-shaped orifice. During musth, a male elephant may urinate with his penis still in the sheath, which causes the urine to spray on the hind legs. An elephant's penis is very mobile, being able to move independently of the male's pelvis, and the penis curves forward and upward prior to mounting another elephant.

In giant anteaters, the (retracted) penis and testes are located internally between the rectum and urinary bladder.

When the male armadillo "Chaetophractus villosus" is sexually aroused, species determination is easier. Its penis can be as long as, and usually remains completely withdrawn inside a skin receptacle. Scientists conducting studies on the "C. villosus" penis muscles revealed this species' very long penis exhibits variability. During its waking hours, it remains hidden beneath a skin receptacle, until it becomes erect and it projects outside in a rostral direction. During its slow wave sleep phase, penile protrusion makes some very complex movements. The penis during this phase is not erect, but remains outside of its receptacle. During paradoxical sleep, no erections occur, and the penile muscles share the characteristics of the rest of the body.

Male turtles and crocodiles have a penis, while male specimens of the reptile order Squamata have two paired organs called hemipenes. Tuataras must use their cloacae for reproduction. Due to evolutionary convergence, turtle and mammal penises have a similar structure.

In some fishes, the gonopodium, andropodium, and claspers are intromittent organs (to introduce sperm into the female) developed from modified fins.

The record for the largest penis size to body size ratio is held by the barnacle. The barnacle's penis can grow to up to forty times its own body length. This enables them to reach the nearest female for fertilization.

A number of invertebrate species have independently evolved the mating technique of traumatic insemination where the penis penetrates the female's abdomen, thereby creating a womb into which it deposits sperm. This has been most fully studied in bed bugs.

Some millipedes have penises. In these species, the penis is simply one or two projections on underneath the third body segment that produce a spermatophore or sperm packet. The act of insemination however occurs through specialized legs called gonopods which collect the spermatophore and insert it into the female.

In male insects, the structure analogous to a penis is known as aedeagus. The male copulatory organ of various lower invertebrate animals is often called the "cirrus".

The lesser water boatman's mating call, generated by rubbing the penis against the abdomen, is the loudest sound, relative to body size, in the animal kingdom.

In 2010, entomologist Charles Linehard described "Neotrogla", a new genus of barkflies. Species of this genus have sex-reversed genitalia. Females have penis-like organs called gynosomes that are inserted into vagina-like openings of males during mating. In 2014, a detailed study of the insects reproductive habits led by Kazunori Yoshizawae confirmed that the organ functions similar to a penis – for example, it swells during sexual intercourse – and is used to extract sperm from the male.

The penis in most male Coleoid cephalopods is a long and muscular end of the gonoduct used to transfer spermatophores to a modified arm called a hectocotylus. That, in turn, is used to transfer the spermatophores to the female. In species where the hectocotylus is missing, the penis is long and able to extend beyond the mantle cavity and transfers the spermatophores directly to the female. Deep water squid have the greatest known penis length relative to body size of all mobile animals, second in the entire animal kingdom only to certain sessile barnacles Penis elongation in "Onykia ingens" may result in a penis that is as long as the mantle, head and arms combined. Giant squid of the genus "Architeuthis" are unusual in that they possess both a large penis and modified arm tips, although it is uncertain whether the latter are used for spermatophore transfer.

The word "penis" is taken from the Latin word for "tail." Some derive that from Indo-European "*pesnis", and the Greek word πέος = "penis" from Indo-European "*pesos". Prior to the adoption of the Latin word in English the penis was referred to as a "yard". The Oxford English Dictionary cites an example of the word "yard" used in this sense from 1379, and notes that in his "Physical Dictionary" of 1684, Steven Blankaart defined the word "penis" as "the Yard, made up of two nervous Bodies, the Channel, Nut, Skin, and Fore-skin, etc."

As with nearly any aspect of the body involved in sexual or excretory functions, the penis is the subject of many slang words and euphemisms for it, a particularly common and enduring one being "cock". See for a list of alternative words for penis.

The Latin word ""phallus"" (from Greek φαλλος) is sometimes used to describe the penis, although "phallus" originally was used to describe "representations", pictorial or carved, of the penis.

Pizzle, an archaic English word for penis, of Low German or Dutch origin, is now used to denote the penis of a non-human animal.

The adjectival form of the word penis is penile. This adjective is commonly used in describing various accessory structures of male copulatory organs found in many kinds of invertebrate animals.

Pizzles are represented in heraldry, where the adjective "pizzled" (or "vilené") indicates that part of an animate charge's anatomy, especially if coloured differently.