A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The strangers in your dreams are actually people that you've seen in real life.
50
Honeybees never sleep.
276
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Bats sleep 18-20 hours per day.
5
The human brain is more active during sleep than during the day.
28
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28