The average person falls asleep in seven minutes.
115
The human brain is more active during sleep than during the day.
28
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34