A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The average cat sleeps about 2/3 of the day.
203
People who sleep late have more mental stamina and can outperform early risers.
33
You forget 90% of your dreams.
256
Cows can sleep standing up, but they can only dream lying down.
745
The strangers in your dreams are actually people that you've seen in real life.
50
44% of kids watch television before they go to sleep.
106