Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
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
47% of people have a nightmare at least once a month.
186
Honeybees never sleep.
276
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Cows can sleep standing up, but they can only dream lying down.
745
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149