This article is interesting it suggests that rooks are as intelligent as monkeys and that they are able to perform complex puzzles in order to source food. Four birds were given a puzzle with a small basket of worms inside a plastic tube. The worms were out of reach but the birds were also given a piece of straight wire. In each case the rooks bent the wire to make it into a tool and then used it to hook the basket of worms out of the tube. Unlike other animals which can learn how to solve a problem by using trial and error the rooks all solved the problem immediately despite never been shown how to do it. Researchers at Cambridge University believe that these results show that rooks have an intelligence to rival chimpanzees who are also able to craft tools using their hands.