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
Sleeping on the job is acceptable in Japan. It is viewed as exhaustion from working hard. Some people fake it to look committed to their job.
57
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
47% of people have a nightmare at least once a month.
186
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Bats sleep 18-20 hours per day.
5
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
Termites work 24 hours per day and they do not sleep.
57