Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Bats sleep 18-20 hours per day.
5
You forget 90% of your dreams.
256
People who sleep late have more mental stamina and can outperform early risers.
33