A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
"Dysania" is the state of finding it hard getting up out of bed in the morning.
33
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
You burn more calories sleeping than you do watching television.
348
Bats sleep 18-20 hours per day.
5
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
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212