One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The strangers in your dreams are actually people that you've seen in real life.
50
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
You burn more calories sleeping than you do watching television.
348
Cows can sleep standing up, but they can only dream lying down.
745