Sea otters hold hands while sleeping so they don’t drift away from each other.
104
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
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
You forget 90% of your dreams.
256
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23