Dogs are a domesticated species of mammals that live in close contact with humans. They are members of the genus Canis, which also includes wolves. Dogs were the first domesticated animals, and have been bred for certain traits, such as speed, size, and fur color, for milleniums. Naturally, dogs are carnivores, but domestic dogs usually consume a diet of starch and meat based food that is produced by people. There are many different species of dogs and they are often considered to be the most popular pet on Earth. Dogs have become an essential part of human life, and perform many tasks for humans.