A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
The average person falls asleep in seven minutes.
115
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
Cows can sleep standing up, but they can only dream lying down.
745