A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The human brain is more active during sleep than during the day.
28
Honeybees never sleep.
276
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
44% of kids watch television before they go to sleep.
106