A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
You can reschedule your sleeping pattern by not eating 12-16 hours before you want to be awake. Upon eating after this time period, your internal clock will reset to a new day, with the time of your first meal being interpreted as "morning".
11
Lack of water is the #1 trigger of daytime fatigue.
148
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
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
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The strangers in your dreams are actually people that you've seen in real life.
50