Chimpanzees are highly intelligent animals.
Their ability to learn, to plan ahead, and to use objects as tools to solve a problem has been demonstrated in field and laboratory observations. Chimpanzees are our closest living relatives. The bonobo is also referred to as the pygmy chimpanzee, although its size does not differ greatly from that of the common chimpanzee. Bonobos are also an endangered species and are restricted to a small region in the lowland rainforests of the Zaire River Basin south of the Zaire River.