Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
47% of people have a nightmare at least once a month.
186
You burn more calories sleeping than you do watching television.
348
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34