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 ...

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 ...

Some animals do it for survival, while others have evolved this ability for different reasons. It might seem strange, but these animals have developed abilities to rest while staying alert to their ...

Wading through a clear knee-deep tidal pool in coastal Florida, I was trying to move slowly, to avoid disturbing a gorgeous American oystercatcher napping on a small sandbar. Oystercatchers are ...

A recent study observed sleeping participants' pupils during sleep, using a new method that could have implications for studying sleep disorders. Reading time 2 minutes Though sleep is a time to power ...