> Chimpanzees are our closest living relatives, sharing more than 98 percent of our genetic blueprint. Humans and chimps are also thought to share a common ancestor who lived some four to eight million years ago. > Chimpanzees live in social communities of several dozen animals, and can habituate themselves to African rain forests, woodlands, and grasslands. > Although they normally walk on all fours knuckle-walking, chimpanzees can stand and walk upright. By swinging from branch to branch they can also move quite efficiently in the trees, where they do most of their eating. Chimpanzees usually sleep in the trees as well, employing nests of leaves. > Chimps are generally fruit and plant eaters, but they also consume insects, eggs, and meat, including carrion. They have a tremendously varied diet that includes hundreds of known foods. > Chimpanzees are one of the few animal species that employ tools. They shape and use sticks to retrieve insects from their nests or dig grubs out of logs. They also use stones to smash open tasty nuts and employ leaves as sponges to soak up drinking water. Chimpanzees can even be taught to use some basic human sign language. > Females can give birth at any time of year, typically to a single infant that clings to its mother's fur and later rides on her back until the age of two. Females reach reproductive age at 13, while males are not considered adults until they are 16 years old. > Although chimps and humans are closely related, the apes have suffered much at human hands. These great apes are endangered and still threatened by bushmeat hunters and habitat destruction.