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 harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
The strangers in your dreams are actually people that you've seen in real life.
50
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
Dieters who sleep more take off more fat that those who sleep less.
159
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The average cat sleeps about 2/3 of the day.
203