A pet or companion animal is an animal kept primarily for a person’s company, entertainment, or as an act of compassion such as taking in and protecting a stray cat, rather than as a working animal, livestock or laboratory animal. Popular pets are often noted for their attractive appearances, intelligence, and relatable personalities. Two of the most popular pets are dogs and cats. Other popular pets include rabbits, ferrets, pigs, rodents such as gerbils, hamsters, chinchillas, guinea pigs, rats, mice, and gophers, birds such as parakeets, doves, and parrots, reptiles such as snakes and lizards, fish and invertebrates such as turtles, frogs and hermit crabs. Smaller pets may include rabbits, guinea pigs, hamsters, gerbils and rodents; fish; reptiles such as turtles and snakes; and invertebrates such as tarantulas and hermit crabs.

Pets provide their owners (or “guardians”) both physical and psychological benefits. Walking a dog can supply both the human and pet with exercise, fresh air, and social interaction. Pets can give companionship to elderly adults who do not have adequate social interaction with other people. There is an emotional bond between humans and their pets that can be beneficial to the pet owner. The care that pet guardians give to their animals also feeds back into the human-animal bond.

In the United States alone there are approximately 86.4 million pet cats and 78.2 million pet dogs. In 2013-14 Australians spent $12.2 billion on their pets which is equivalent to $530 per household. 65% of households in the UK have at least one pet. It has been estimated that around 44% of UK households have a dog.