Many kinds of Old World monkeys have cheek pouches much like those of hamsters and squirrels. The pouches enable the monkeys to store food temporarily. No New World monkey has these pouches. Arms and legs. Monkeys usually walk and run on all fours, either on tree branches or on the ground.
Most species have legs that are slightly longer than their arms.
Many kinds of monkeys can stand and even run on their legs, but only for a short period of time. Monkeys usually stand or run on their legs when carrying food, peering over high grass, or threatening enemies or members of the group. Hands and feet. This enables a monkey to grasp small food items. Most kinds of New World monkeys have thumbs that are only partly opposable.