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
Cows can sleep standing up, but they can only dream lying down.
745
Honeybees never sleep.
276
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
The strangers in your dreams are actually people that you've seen in real life.
50