Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
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
Those who get out of bed by 7am are more likely to be thinner and happier.
20
Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
15
The strangers in your dreams are actually people that you've seen in real life.
50