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
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
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
Termites work 24 hours per day and they do not sleep.
57
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
Those who get out of bed by 7am are more likely to be thinner and happier.
20
Bats sleep 18-20 hours per day.
5