Old World monkeys come in lots of shapes, sizes, and colors. They can be divided into two subfamilies—the Cercopithecinae and the Colobinae. The cercopithecines eat fruit and many other types of food, and they have big cheek pouches for carrying it. The colobines are usually more slender and lack cheek pouches. They mainly eat leaves and are often called leaf monkeys. Leaf eaters have special stomachs that help them break down and digest their leafy food.

Old World monkeys come in lots of shapes, sizes, and colors. They can be divided into two subfamilies—the Cercopithecinae and the Colobinae. The cercopithecines eat fruit and many other types of food, and they have big cheek pouches for carrying it. The colobines are usually more slender and lack cheek pouches. They mainly eat leaves and are often called leaf monkeys. Leaf eaters have special stomachs that help them break down and digest their leafy food.