Termites work 24 hours per day and they do not sleep.
57
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
You forget 90% of your dreams.
256
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
Dieters who sleep more take off more fat that those who sleep less.
159
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