Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
Termites work 24 hours per day and they do not sleep.
57
The human brain is more active during sleep than during the day.
28
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
Cows can sleep standing up, but they can only dream lying down.
745
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28