Their liveliness makes them favorites in zoos. Because of the similarities between monkeys and humans, scientists have used monkeys in research on human behavior and disease. There are about 200 species of monkeys. Most of them live in tropical regions in Central and South America, Africa, and Asia. Most species live in forests and some spend their entire life in the trees.
All monkeys live together in various kinds of groups.
Some kinds of monkeys Monkeys vary greatly in size. Scientists classify monkeys into two major groups, New World monkeys and Old World monkeys. New World monkeys live in Central and South America, and Old World monkeys are found in Africa and Asia. The two groups differ in several ways. For example, New World monkeys have nostrils spaced widely apart.