Chimpanzees are social animals that live in communities and bonds between individuals are sometimes quite strong. A dominant male rules, though power coalitions exist consisting of individuals of both sexes. A male who cannot solicit the support of these coalition groups will eventually lose his dominance. Communities guard their territories and may attack and kill outsiders. Whole communities have been known to be killed off by stronger neighboring communities as they take over the range.
Communication is complex, involving a variety of facial expressions, gestures and vocalizations.
Captive animals have even learned to communicate with humans using sign language. Mutual grooming is essential in maintaining friendly relationships, though it is also often used to gain favors. Males stay in a natal group and travel together. Females emigrate to new groups. Older females are more popular with males than younger individuals who often have to leave the community, either temporarily or permanently, in order to mate.