When I was a kid, they said that tool use was what separated humans from other animals, but then chimps were discvovered using sticks and reeds to extract termites from nests. According to wikipedia, tool use is seen in other animals besides chimps, including elephants, otters, dolphins, birds and octopuses. It doesnt surprise me. Given the whole concept of evolution you would expect most human behaviors to be present in some rudimentary form in other animals rather than just pop into human existance fully formed. Tool use seems to me just a modification of many types of animal behavior. There was a robin that built a nest on my porch. Every few days I would find clumps of moss on the cement. I thought it had fallen out out of the nest and kept sweeping it off the porch. The next day there would be more. I finally realized the bird was collecting it and drying it in the sun before he incorporated it into the nest. This isnt really making a tool, but its close, since the moss had to deliberately modified before use. And of course beavers do similar things. Traditionally people have said this kind of behavior is mindless and instinctive, but I'm not sure how one can be prove that. I assume "instinctive" behavior simply means "not learned," that the animal will do it without having seen another animal do it first. Yet many animals do seem to adapt instinctive behaviors to new situations through trial and error, just like humans. For example, not all lakes or streams are exactly alike and beavers would have make certain some unique adjustments to their constructions, solve problems so to speak. Even my cat discovered that if he climbs up on the porch railing and taps on my daughter's bed room window with his paw, she will let him in the house. How did he come up with that idea the first time?