The strangers in your dreams are actually people that you've seen in real life.
50
You burn more calories sleeping than you do watching television.
348
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
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
You forget 90% of your dreams.
256
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13