A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
You burn more calories sleeping than you do watching television.
348
If you hold farts in during the day, they'll just come out when you sleep.
16
Termites work 24 hours per day and they do not sleep.
57
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