Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
Honeybees never sleep.
276
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
Bats sleep 18-20 hours per day.
5
People who sleep late have more mental stamina and can outperform early risers.
33
The human brain is more active during sleep than during the day.
28