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
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
There's a love mattress that is specifically designed for couples who sleep on each other's arms.
12
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
Cows can sleep standing up, but they can only dream lying down.
745