Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Cows can sleep standing up, but they can only dream lying down.
745
You burn more calories sleeping than you do watching television.
348