On the ground, they run on all fours, but walk upright with toes turned inwards. While on all fours, they support the weight of their body on the knuckles of their hands. Chimps are scared of falling from trees and rarely swing by their arms as gibbons and orangutans do. Chimpanzees are mainly vegetarians, eating leaves, roots, and fruits like wild figs. But they sometimes eat birds, small rodents, and insects.
Wild chimps spend about seven hours a day looking for food, either up in the trees or on the ground.
Crevices and cracks in logs are searched for insects, and nests are robbed for eggs and chicks. Sometimes they use rocks for breaking open tough fruits. When food is plentiful, a large group of chimps assembles for a feast. Adult males drum on the buttress roots of trees or on the ground and other chimps join in a loud hooting chorus. This noise can be heard a long way off, attracting other chimps as well.