Dieters who sleep more take off more fat that those who sleep less.
159
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The human brain is more active during sleep than during the day.
28
Cows can sleep standing up, but they can only dream lying down.
745
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22