Every animal with a brain needs sleep — and even a few without a brain do, too. Humans sleep, birds sleep, whales sleep and even jellyfish sleep. Sleep is universal “even though it’s actually very ...

Tired of ads? Subscribers enjoy a distraction-free reading experience. Every animal with a brain needs sleep — and even a few without a brain do, too. Humans sleep, birds sleep, whales sleep, and even ...

Animals that navigate extreme conditions and environments have evolved to sleep in extreme ways — for example, stealing seconds at a time during around-the-clock parenting, getting winks on the wing ...