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
If you hold farts in during the day, they'll just come out when you sleep.
16
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
You forget 90% of your dreams.
256
You burn more calories sleeping than you do watching television.
348
Bats sleep 18-20 hours per day.
5
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149