A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The strangers in your dreams are actually people that you've seen in real life.
50
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Cows can sleep standing up, but they can only dream lying down.
745
"Dysania" is the state of finding it hard getting up out of bed in the morning.
33
Sea otters hold hands while sleeping so they don’t drift away from each other.
104