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 harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
Honeybees never sleep.
276
You burn more calories sleeping than you do watching television.
348
The strangers in your dreams are actually people that you've seen in real life.
50