Researchers have found that rooks, a member of the crow family, are capable of using and making tools, modifying them to make them work and using two tools in a sequence. The rooks quickly learned to drop a stone to collapse a platform and acquire a piece of food, and subsequently showed the ability to choose the right size and shape of stone without any training.
Not only could they use stones to solve the task, but they were flexible in their tool choice, using and modifying sticks to achieve the same goal. When the correct tool was out of reach, they used another tool to get it, demonstrating the ability to use tools sequentially. They also bent a straight piece of wire to make the hook to reach the food.