03/01/2014 - Birds do it, bees do it...yet science still can't answer the basic question: why do we sleep? Every creature on the planet sleeps - from giant humpback whales to teeny fruit flies. What does it do for us, and what happens when we go without it? We take a peek at iguanas sleeping with one eye open, get in bed with a pair of sleep-deprived new parents, and eavesdrop on the uneasy dreams of rats.
