For centuries, the use of tools was believed to separate humanity from the animals. However, in the 1960s, Jane Goodall discovered that wild chimps manipulate branches and stems for use in getting honey out of hives and termites out of their mounds. Other discoveries of tool use by animals soon followed.
Chimps also carry rocks around, which they use to crack open nuts.
Orangs hold large leaves over themselves to protect them from sun or rain, throw sticks at humans in self-defense, and chew up mouthfuls of leaves to make sponges to soak up rainwater. Flakes are formed by smashing one rock onto another. Making sharp flakes is not as easy as it might seem. In addition to generating enough force, the angle of the blow and its position on the rock are crucial. Stone-tool expert Nick Toth, an anthropologist renowned for carrying rocks with him in his briefcase wherever he goes, wanted to know whether apes could create the same types of tools early human ancestors fashioned from stone.