They identified two states: a “normal” one and a quiet state. When they were in this quiet state, the jellyfish were much ...

A new study analyzed the sleep patterns of jellyfish and sea anemones and found they share some sleep traits with humans. The ...

Studying ancient sea creatures’ snoozing habits could shed light on the origins of sleep.

Sleep is one of life’s most universal behaviors. Despite its ubiquity, it’s also one of the most mysterious. Humans spend ...

Animals have evolved to sleep in extreme ways — for example, taking micro naps during parenting, sleeping on the wing during ...

Some animals can sleep with just half their brain at a time. Understanding this phenomenon can help us learn more about human ...

A protective mucous cocoon surrounds this parrotfish as it sleeps in Australia's Great Barrier Reef. This layer of protection helps fend off predators so parrotfish can get a good night's rest.

In jellyfish and sea anemones, neurons accumulate DNA damage while animals are awake and repair that damage during sleep.