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
You forget 90% of your dreams.
256
Bats sleep 18-20 hours per day.
5
Dieters who sleep more take off more fat that those who sleep less.
159
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
People who sleep late have more mental stamina and can outperform early risers.
33
The strangers in your dreams are actually people that you've seen in real life.
50
The human brain is more active during sleep than during the day.
28