A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Lack of water is the #1 trigger of daytime fatigue.
148
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
Those who get out of bed by 7am are more likely to be thinner and happier.
20
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 average person falls asleep in seven minutes.
115