Archaeological evidence shows that chimps have been using tools in the western forest of Ivory Coast for about 4000 years.

BBC report here, PNAS article here.

It now appears that chimps not only use rocks and sticks, they also use ”spears”, according to this latest article in Current Biology (open access). Females pick up tool use quicker than males, which may have implications for the evolution of tool use in our species. BBC summary here.