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
Dieters who sleep more take off more fat that those who sleep less.
159
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Termites work 24 hours per day and they do not sleep.
57
"Dysania" is the state of finding it hard getting up out of bed in the morning.
33
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34