Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
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
Cows can sleep standing up, but they can only dream lying down.
745
Sea otters hold hands while sleeping so they don’t drift away from each other.
104