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 average person falls asleep in seven minutes.
115
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
Cows can sleep standing up, but they can only dream lying down.
745
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
You burn more calories sleeping than you do watching television.
348