A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The average cat sleeps about 2/3 of the day.
203
Termites work 24 hours per day and they do not sleep.
57
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
People who sleep late have more mental stamina and can outperform early risers.
33
Cows can sleep standing up, but they can only dream lying down.
745
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