I saw a story on crows being tool users and tool makers. They had 2 crows, mail and female in a cage with straight and curved pieces of wire. The mail being larger took the curved wire and hooked some food. The female took a straight piece of wire, wedged it in a crack and bent it into a hook. Then it hooked the food. The female also bent a wire by standing on one end and pulling on the other.

Very smart critters.