With up to one million hairs per square inch of its body, the sea otter has the densest fur in the animal kingdom. (To put this in perspective, you’ve probably only got 100,000 hairs or less on your whole head!) Together with a huge lung capacity, this makes these water-loving creatures extremely buoyant. The pups are born so buoyant, they're incapable of diving underwater, and are often left bobbing on the surface in a sea kelp bed while their mothers hunt for food nearby.
