You aren't alone in your nightly tossing and turning. Sea lions do it, too. A new video by National Geographic details the strange ways different animals sleep. Walruses, for example, can sleep floating vertically in the water, their heads bobbing above the waves. When hippos sleep in water, some sleep under the water, occasionally popping up to take a breath. The most disturbingly odd sleeping style in the animal kingdom is, of course, the human grandfather.