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

The animal kingdom is full of fascinating adaptations, and one of the most intriguing is the ability to sleep with one eye open. While humans drift into deep slumber with both eyes closed, several ...

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

Have you heard the saying about “sleeping with one eye open”? It’s a bit of metaphoric advice about staying vigilant—and a way to describe very light restless sleep. But sleeping with eyes open is ...