The strangers in your dreams are actually people that you've seen in real life.
50
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
If you hold farts in during the day, they'll just come out when you sleep.
16
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
Bats sleep 18-20 hours per day.
5
The average person falls asleep in seven minutes.
115