The cat (Felis catus), also known as the domestic cat or housecat^[5] to distinguish it from other felines and felids, is a small domesticated carnivorous mammal that is valued by humans for its companionship and its ability to hunt vermin and household pests. Cats have been associated with humans for at least 9,500 years,^[6] and are currently the most popular pet in the world.^[7] Due to their close association with humans, cats are now found almost everywhere on Earth. Their adaptability, rapid breeding rate, and predatory instincts make them effective hunters. In some locations, cats have affected indigenous animal populations; this has led them to be classified as an invasive species in some areas. Most problems are caused by the large number of feral cats worldwide, with a population of up to 60 million of these animals in the United States alone.^[8] Failure to control the breeding of pet cats by spaying and neutering and the abandonment of former household pets cause the development of such feral colonies.

Cats are similar in anatomy to the other felids, with strong, flexible bodies, quick reflexes, sharp retractable claws, and teeth adapted to killing small prey. Nocturnal predators, cats use their acute hearing and ability to see in near darkness to locate prey. Not only can cats hear sounds too faint for human ears, they can also hear sounds higher in frequency than humans can perceive. This is because cats' usual prey -- rodents and other small mammals, small reptiles, and birds -- make sounds that are higher in frequency. Cats' hearing is "tuned" to those higher sounds. In addition to acute hearing, cat’s ears are equipped with more than a dozen muscles that enable them to swivel 180 degrees toward the source of sounds.

Cats have relatively few taste buds compared to our own. Their taste buds respond to salt, sour, and bitter flavors, but have very few that respond to the taste of sugar. Protein-based tastes activate the taste buds, but the taste of fats are largely registered as smells rather than tastes. Therefore, a preference to one kind of meat over another is mostly a difference in scent rather than taste.

Despite being solitary hunters, cats are a social species and use a variety of vocalizations, pheromones and types of body language for communication. These include meowing, purring, trilling, hissing, growling, and grunting.^[9] They are also bred and shown as registered pedigree pets. This hobby is known as cat fancy.

As The New York Times wrote in 2007, "Until recently the cat was commonly believed to have been domesticated in ancient Egypt, where it was a cult animal."^[10] A study that year found that the lines of descent of all house cats probably run through as few as five self-domesticating African Wildcats (Felis silvestris lybica) circa 8000 BC, in the Near East.^[4] The earliest direct evidence of cat domestication is a kitten that was buried with its owner 9,500 years ago in Cyprus.^[11]