Monkeys are highly intelligent animals that use a range of facial expressions, postures and body movements as well as vocalizations to communicate with each other. They are also skilled problem-solvers and can use tools. Unlike other primates, monkeys have large brains relative to their body size and are diurnal (active during the day). Most types of monkey are troops consisting of closely related females with their young and either a single male or several males who do not live with their offspring.
Most species of monkey are found in rainforest regions though a few, like the colobus monkey, are tropical tree dwellers while others like geladas and golden monkeys reside in mountain areas. Those that inhabit savannah areas like baboons and guenons spend most of their time on the ground rather than in trees but can climb them when needed.
In general, monkeys are very social animals and they live in groups called troops that may number from a few individuals to thousands or even millions of them. Almost all monkeys are diurnal and most have a strict social hierarchy. They are highly mobile, scouring their home territory for food and often scatter seeds as they travel.
Despite their highly developed social structures, most monkeys are not very affectionate toward one another. However, some species such as the marmoset and tamarin form close friendships and rivalries in an effort to survive. Infants are helpless at birth and get a ride on their mother’s fur or cling to their parents for care until they can look after themselves.