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
Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
15
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
Termites work 24 hours per day and they do not sleep.
57