A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
44% of kids watch television before they go to sleep.
106
Termites work 24 hours per day and they do not sleep.
57
The human brain is more active during sleep than during the day.
28
Cows can sleep standing up, but they can only dream lying down.
745
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212