Lack of water is the #1 trigger of daytime fatigue.
148
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
The strangers in your dreams are actually people that you've seen in real life.
50
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
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23