animal sleep– tag –

Cover photograph: “Fkeysmacro.jpg” by Chris Hind, licensed under CC BY 3.0. A motionless animal might be asleep. It might also be awake, waiting for prey or resting quietly. To tell the difference, researchers look beyond stillness: how ...

Cover photograph: Peter Schmidt How does a koala spend its day? Curled into the fork of a tree, it may remain almost motionless for hours. It looks asleep, but some of that time may be spent resting while awake. At the other extreme, a s...

Cover photograph by Simone Dinoia Sleep takes time away from finding food, moving about and watching for danger. Yet humans and many other animals regularly make time for it. Sleep—or a state with some of its defining features—has been r...