A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The strangers in your dreams are actually people that you've seen in real life.
50
Those who get out of bed by 7am are more likely to be thinner and happier.
20
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
Cows can sleep standing up, but they can only dream lying down.
745