Many monkey species are tree-dwelling although there are species that live primarily on the ground, such as baboons Most species are mainly active during the day. Monkeys are generally considered to be intelligent, especially the Old World monkeys.

Monkeys are tailed primates found mostly in the tropical forests of Africa, Asia, and South America.They split into Old World monkeys (narrow noses, no prehensile tails) and New World monkeys (flat noses, often with gripping tails).