We've known for years that chimps employ rocks to smash nuts and sticks to dig out yummy termites. Scientists have now for the first time observed gorillas also using tools. In the rainforest of Congo, a female gorilla used a stick to test how deep the water was before wading into a pool. Another gorilla used a turned a broken off tree trunk into cane to lean on. Until now, gorillas were seen as the big lugs of the primates: obviously not.