Their communities are made up of several subgroups. Among the males there is a loose hierarchy but no overall leader. Within the community, these groups are quite fluid, with adults wandering off and joining other groups. Mother chimps will often form attachments with offspring and stay with them as a group. Between communities, there is a lot of hostility.
Chimpanzees spend a lot of time grooming each other.
This strengthens their social bond. Chimpanzees communicate vocally, with facial expressions, and with gestures. Females give birth to a single young chimp after about 8 months. Young chimpanzees are born helpless and spend the first 6 months clinging to the hair on its mother's chest while she is in motion. From 6 months to 2 years, young chimpanzees ride on the mother's back.