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 human brain is more active during sleep than during the day.
28
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
You burn more calories sleeping than you do watching television.
348
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
Dieters who sleep more take off more fat that those who sleep less.
159
The strangers in your dreams are actually people that you've seen in real life.
50