It's been said that crows have the problem-solving abilities of a 5-year-old human child. Seeing as plenty of adult humans seemingly don't have the problems-solving abilities of a 5-year-old human child, this is quite a feat. The classic test for problem-solving ability is the good old tube-and-stick test in which a piece of food is place at the bottom of a tube, and the animal must use the wire stick to retrieve it. Primates will usually use the stick to stab the food and ease it out, but the crows have come up with an even better solution. Without having to be shown, or watching any other crow figure it out, the New Caledonian Crow will actually bend the end of the wire to create a hook, enabling it to pull the food out with ease. This behaviour makes them the only non-human to actually invent a new tool out of an existing one, as opposed to just figuring out how to use the old one. In one experiment, the crows had a choice between a hooked piece of wire and a straight one. They immediately went for the hooked one, but when one of them stole and made off with it, the second crow actually took the straight wire and bent the end round to create a new tool like it ain't no thang. Oh, and the crows had never seen wire before. In further experiments, they have also been known to used stones to raise the level of water in a tube and reach the food floating on top, a solution that a lot of human adults would probably struggle to get to. Scientists are thinking of moving them on to sudokus next.
