Chimpanzees eat mainly plants, including fruits, leaves, and seeds. They also eat insects and birds’ eggs. Sometimes chimpanzees hunt and eat monkeys and other mammals.
On the ground chimpanzees can walk upright on two legs. But more often they lean on their knuckles and walk on all fours. Chimpanzees spend time both in trees and on the ground.
Chimpanzees make and use a variety of simple tools. For instance, some chimpanzees chew certain leaves to make them spongy. Next, they push the leaves into tree hollows filled with water. They use sticks to get their leaf-sponges back out. Finally, they drink the water from the leaves. Young chimpanzees probably learn how to use tools by watching and imitating adults.
Chimpanzees live in groups of about 15 to 120 individuals, led by a male. Members of a group are generally friendly toward each other but unfriendly to other groups. Sometimes one group will attack a smaller group and try to take its land.
