A new video by National Geographic shows the bizarre ways different animals sleep. Walruses sleep while floating vertically in the water. They keep their heads above the waves. When hippos sleep in water, some sleep under the water. These smart guys will pop up to take a breath. Of course, you know about bats and their against the gravity sleep.
But do you know about the similarity between sea lion's sleep and human's sleep? Let's find out. Hit play...
