If you hold farts in during the day, they'll just come out when you sleep.
16
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
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
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
Those who get out of bed by 7am are more likely to be thinner and happier.
20