Chimpanzees (Pan troglodytes) can be found from southern Senegal across the forested belt north of the Congo River to western Uganda and western Tanzania. They live in fission-fusion societies of up to 150 individuals, splitting up into small groups when traveling or foraging during the day and coming back together to sleep at night. There is a distinct linear dominance hierarchy in male chimpanzees, and males are dominant over females. They are generally fruit and plant eaters, but they also consume insects, eggs, and meat. Chimpanzees employ tools to gain access to food. Chimpanzees groom each other daily, and this activity has important social functions such as calming individuals and solidifying their bonds with each other.