The common chimpanzee is a frugivorous species, but will also consume seeds, nuts, flowers, leaves, pith, honey, insects, eggs, and vertebrates, including monkeys. During the dry season when fruit becomes scare seeds as well as bark, flowers, resin, pith, and galls are important food resources. The common chimpanzee will use 300 different plant species per year, and about 20 different plant species per day (Estes, 1991). This species will supplement their diet with termite clay and rocks consumed for the minerals (Nishida and Hiraiwa-Hasegawa, 1987). The common chimpanzee is a capable hunter, usually the males form bands to hunt. They will hunt antelopes, pigs, duikers, and monkeys. One primate species in particular that the common chimpanzee often hunts is Procolobus badius. The individual who makes the kill in the hunting party is the one who eats most of the prey, others hold out their hands and beg for food, usually they get some. The common chimpanzee hunts opportunistically, and groups will quickly form when the time is right (Estes, 1991). Tool use is found in this species, and the common chimpanzee uses tools to extract insects and to crack open nuts. The western common chimpanzee will use a hammer-anvil system to crack open oil-palm nuts (Estes, 1991). They first select a stone with which to use as a hammer, and then they place a nut on another larger stone, finally breaking open the nut with the hammer-stone (Estes, 1991). Individuals may use the same stone over and over again. The species of nuts they use hammers on most often is Coula edulis and Panda oleosa (Estes, 1991). The western common chimpanzee also uses wooden clubs instead of stones as hammers, and females are able to break open Coula nuts in the trees instead of bringing them down to an anvil (Estes, 1991). Panda nuts are the most difficult to break open, and only females have the patience to do so (Estes, 1991). The eastern subspecies forages for the same species of nuts, but does not break them open with tools, rather eating the skin off of the surface; this suggests some degree of differentiation amongst the subspecies, regional culture. The central common chimpanzee will use sticks that are specially selected to fish termites out of a mound (Estes, 1991). Termites will attack anything the comes into the nest, and the central common chimpanzee will exploit this behavior and insert a stick into a hole and lick up the termites that are on the stick. Eastern common chimpanzees use this behavior also, but instead of termites they will fish for ants, there is local variation amongst groups for what insect species they will fish for (Estes, 1991). Infants learn the various tool use behavioral patterns by watching their mothers do the behavior, and they even try to imitate their mothers when they are either cracking nuts or fishing for insects. The common chimpanzee is a diurnal and a semi-terrestrial species. Every night every common chimpanzee, except for the infants, will construct a nest made of branches and leaves up in a tree (Estes, 1991). Usually the tree is one the were foraging near during the day, and members of the group, except for adult and subadult males, will build their nests near each other (Estes, 1991).