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 your stomach can induce weirder, scarier, and sexier dreams.
22
Termites work 24 hours per day and they do not sleep.
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Bats sleep 18-20 hours per day.
5
Lack of water is the #1 trigger of daytime fatigue.
148
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.
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The strangers in your dreams are actually people that you've seen in real life.
50