Ancient people might have invented tools after watching animals. A mole digs underground tunnels by scooping soil with its big paws. This is similar to the shovel people use to dig. Beavers gnaw trees with their front teeth to cut them down so they can build dams. This is similar to the chisels people use. Vultures crack the shells of ostrich eggs by using stones. Some ants cut leaves with their jaws. Many of the tools people have invented work like animal body parts.