A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Termites work 24 hours per day and they do not sleep.
57
Lack of water is the #1 trigger of daytime fatigue.
148
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
The human brain is more active during sleep than during the day.
28
Cows can sleep standing up, but they can only dream lying down.
745
There's a love mattress that is specifically designed for couples who sleep on each other's arms.
12