Humans are classified as mammals. Like other mammals, humans have body hair, suckle their young with milk produced from special glands on their chests, possess differentiated teeth and a four-chambered heart, and become pregnant rather than lay eggs.
Humans are most closely related to the mammalian group called the primates. Primates include all the great apes and the many different kinds of monkeys. Humans and other primates are particularly known for their large brains, relative to their body size.
Other notable mammal groups include rodents and carnivores. Rodents are small-to-medium-sized gnawing creatures, such as rats and beavers. Carnivores are furry predators, including domesticated dogs, domesticated cats and their relatives.
All mammals possess a neocortex, a region of the brain that is involved in many complex conscious functions, such as sensory perception and thought. In primates and humans, this region is very developed.