Giraffes snooze in the most unexpected positions, surprising and delighting onlookers.

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 ...

Sleep is supposed to be the ultimate vulnerability. You shut down, your reactions slow, and the world keeps moving without you. For decades, sleep scientists have treated long, regular bouts of sleep ...