"Capuchin" is a French word taken from Italian "cappucino," meaning "hooded one." Thus, also, the order of monks who wore hooded robes.

The capuchin's body is nimble and slender, with thin limbs as well. The thumbs and big toes are opposable to the other fingers and toes. The head is round with short hairs at the back which are darker than the rest of the coat. The long tail is covered with hair and is partly prehensile. Length of head and body one to two feet, tail about the same, weight 3 to 9 lbs.

Capuchins are strictly tree dwellers, some species leaving the trees only to drink. They live in lively troops ranging in size from a small family group to a loose group of up to 40 individuals. They are extremely active and forage for prey by examining leaves, picking through dead litter, splitting twigs and pulling off bark. They spend most of their day foraging for food and travelling in the tree tops of the forest. Each troop keeps to regular tracks through the forest and has a small but regular range, which may overlap the ranges of other troops. They move through the canopy in single file and in a regular order. First come the half-grown young of both sexes, followed by the adult females and the adult males, the females with young bringing up the rear. The troop communicates with a variety of chatters, squeaks, shrieks, and other sounds.

These small monkeys are preyed upon by jaguars and large birds of prey, but are hunted little by man because their flesh is not so tasty as that of spider and woolly monkeys.

Capuchins are popular in zoos and laboratories because of their intelligence, which is often as great as chimpanzees. They use insight to work out problems in their environment, and use sticks and other tools for obtaining food. Some have even learned to use a hammer in captivity to open nuts and other hard food containers.