Scientists once thought that only humans and our closest relatives, chimps, were smart enough to use tools. But as our documenting of the natural world has gotten more detailed—and as we’ve become, perhaps, less haughty about our supposed superior intellect—we’ve found that many species...

Scientists once thought that only humans and our closest relatives, chimps, were smart enough to use tools. But as our documenting of the natural world has gotten more detailed—and as we’ve become, perhaps, less haughty about our supposed superior intellect—we’ve found that many species...