If you hold farts in during the day, they'll just come out when you sleep.
16
You burn more calories sleeping than you do watching television.
348
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
47% of people have a nightmare at least once a month.
186
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
The human brain is more active during sleep than during the day.
28
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