A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
If you hold farts in during the day, they'll just come out when you sleep.
16
Cows can sleep standing up, but they can only dream lying down.
745
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
The average cat sleeps about 2/3 of the day.
203
The strangers in your dreams are actually people that you've seen in real life.
50