Continuous sleep is a modern habit, not an evolutionary constant, which helps explain why many of us still wake at 3 am and wonder if something's wrong.

For hundreds of years, night didn't mean a long sleep. Long before electric lights lit up homes and streets, people lived ...

Sleeping is known to help humans stabilize information and tasks learned during the preceding day. Now, researchers have found that sleep has similar effects upon learning in starlings, a discovery ...

On dry nights, the San hunter-gatherers of Namibia often sleep under the stars. They have no electric lights or new Netflix releases keeping them awake. Yet when they rise in the morning, they haven’t ...

Ancient humans did not sleep continuously. They commonly slept in two shifts each night, separated by a period of wakefulness. This practice changed over the last two centuries. Artificial lighting ...

A new study analyzed the sleep patterns of jellyfish and sea anemones and found they share some sleep traits with humans. The research could provide insight into the origins and function of sleep.