We think of the Stone Age as something that early humans lived through. But we are not the only species that has invented it.
“Tool Use In Animals”, a tidy little informative set of pages from Dr. Robert Cook's much larger “Animal Cognition & Learning Website” at Tufts University. See also (worth repeating because it’s the coolest thing ever) the previously featured “Betty the Crow”. ◊via milovoo in Ask MetaFilter◊