Sea otters hold hands while sleeping so they don’t drift away from each other.
104
The average cat sleeps about 2/3 of the day.
203
47% of people have a nightmare at least once a month.
186
You burn more calories sleeping than you do watching television.
348
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