Bats sleep 18-20 hours per day.
5
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
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 higher someone’s I.Q. the more likely they are to be sleep deprived.
29
Lack of water is the #1 trigger of daytime fatigue.
148
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
You forget 90% of your dreams.
256