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
Those who get out of bed by 7am are more likely to be thinner and happier.
20
If you hold farts in during the day, they'll just come out when you sleep.
16
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
Cows can sleep standing up, but they can only dream lying down.
745
You forget 90% of your dreams.
256
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23