Most live in the warm lowlands.

The pygmy marmosets of South America are the smallest.

They are about six inches (15 cm) long.

The African baboon is the biggest.

Its body is about two feet (60 cm) long

They can weigh up to 165 pounds (75 kg).

They are aggressive and dangerous to humans.

The rhesus is considered highly intelligent.

The capuchin makes a good pet.

Most monkeys feed and travel in large groups.

While their main diet is leaves, fruit and grain, they also eat insects and birds.

The South American owl monkey, or douroucouli, sleeps during the day and hunts at night.

Basically, the Old World is Asia, Europe and Africa, while the New World is the Americas. Animals can be described as from the New or Old World.

Only New World monkeys have prehensile tails.

They have thick pads of skin.

Old World monkeys have nostrils that are close together and point downward. New World monkeys have flat noses with the nostrils set far apart and open toward the side.

The Barbary ape lives in Gibraltar.

It is a black-and-white colobus monkey, found in East Africa and Nigeria. The guereza was hunted for its fur, which was used to trim women's dresses.

The patas monkey can reach a speed of 34 miles per hour (55 kph).

The proboscis monkey has a particularly long nose. An old male of the species may have a nose three inches (8 cm) long.