Cows can sleep standing up, but they can only dream lying down.
745
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
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
47% of people have a nightmare at least once a month.
186
Those who get out of bed by 7am are more likely to be thinner and happier.
20
You burn more calories sleeping than you do watching television.
348
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212