How some animals evolved extreme ways to sleep in dangerous environments

The albatross is said to be able to sleep while flying. — Photos: Pixabay

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 risky”, said Paul-Antoine Libourel, a researcher at the Neuroscience Research Center of Lyon in France.