It is called a "Squirrel" monkey because it is not very big - about as big as a squirrel - 10-14 inches. Males are larger than females. Their fur is short, thick, soft, and grayish, yellowish and in some places greenish.

The upper part of their head is hairy. This black and white face gives them their German name, "skull monkeys".

At one time, squirrel monkeys were imported into the United States as research animals or as pets (they are extremely hyper pets!)

Females have black fur on their heads. Males have gray fur on their heads.

They do not use their tails for grasping as some monkeys do. The tail is used for balance.

A squirrel monkey will spray urine on the bottoms of his hands and feet. Other monkeys can smell this as it marks the territory. They also distribute a musky glandular secretion throughout their fur (especially the tail) to mark territory or to leave a trail for other members of the troop to follow as they go through the trees. This odor deters hunters who might otherwise kill them for food.