Monkey is the common, or non-scientific, name used to refer to several species of primates, the group of mammals that also includes humans. The majority of monkey species live in trees, but there are several that live primarily on the ground. Most monkeys are herbivorous and primarily eat large amounts of fruit. Some species are omnivorous, however, adding insects and a wide range of other foods to their diets.
Chimpanzees and bonobos are the closest living relatives to our species, Homo sapiens. Humans and these two members of the Pan genus all descended from a common ancestor that lived about 6-7 million years ago.