Dogs are a member of the order Carnivora. Dogs have been domesticated since ancient times, and are a descendant of extinct Pleistocene wolves and modern wolves. Dogs are able to adapt well into human households and communities because of their natural sociability, trainability, and playfulness. Their ability to perceive smells allows them to communicate important information and can be useful in hunting, herding, guarding property and children, tracking people or animals, and sniffing out smuggled goods on cargo ships.
The ability to linger on scents for long periods of time is one of a dog’s most valuable skills. For example, some dogs can follow a trail of air or ground scents over four times as far as humans can. They also have excellent hearing, especially those with more natural ear shapes like those of wild canids, and can hear sounds at lower and higher frequencies than humans.
Throughout history, dogs have been prized as companions, family pets, herders, trackers, and hunting and service animals. They have even been interred with kings and other royalty, as they are believed to bring good luck in the afterlife.
In the modern world, dogs are found in every environment and serve a wide variety of important purposes. They are loyal companions that enjoy being petted and will wag their tails with pleasure when shown affection. However, if mistreated, they may growl or snap in self-defense. As with any pet, dogs require food, shelter, grooming, and veterinary care, as well as routine vaccinations. They are susceptible to diseases and ailments that affect humans, such as rabies and distemper, and can also suffer from genetic conditions like hip dysplasia, luxating patellas, and epilepsy.