The crows travel with their tools, suggesting they value them; they know a good tool when they see one and keep it for reuse. There’s something almost outlandish about this behavior. Birds making a tool so good they want to reuse it? Plenty of animals use tools. But few make such elaborate ones. In fact, as far as we know, only four groups of animals on the planet craft their own complex tools: humans, chimps, orangutans, and New Caledonian crows. And even fewer make tools they keep and reuse.
