Sleeping underwater might sound peaceful — but for ocean animals, it’s a matter of survival. Some dolphins sleep with one half of their brain at a time, keeping one eye open to avoid danger and ...

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 ...

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 in fish may look different from humans, but rest is essential for survival. Here’s what experts have to say about fish sleep. A protective mucous cocoon surrounds this parrotfish as it sleeps in ...

What has puzzled researchers and philosophers for many centuries is the ‘why’ of sleep, along with the ‘how’. We human animals know from experience that we need to sleep, and that the longer we go ...