Cows can sleep standing up, but they can only dream lying down.
745
Dieters who sleep more take off more fat that those who sleep less.
159
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 human brain is more active during sleep than during the day.
28
People who sleep late have more mental stamina and can outperform early risers.
33
You burn more calories sleeping than you do watching television.
348
Bats sleep 18-20 hours per day.
5