All animals sleep, although we really don't know why. We have several theories, but there is no consensus on the matter. Animals don't all sleep the same way. Elephants sleep only a few minutes at a time, while cats sleep most other lives. And dolphins only sleep with half their brains at a time!
Ed Yong tells us about research into how different animals sleep. One thing we're sure about -you have to get the right amount of sleep to function properly. I've been reading Yong's science articles for years, and this is the first time I've ever heard him speak. Up until now, I've read those articles in an American accent, but will read them in a British accent from now on. -via The Atlantic