The human brain is more active during sleep than during the day.
28
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
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
The average cat sleeps about 2/3 of the day.
203
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
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