Cows can sleep standing up, but they can only dream lying down.
745
Honeybees never sleep.
276
Dieters who sleep more take off more fat that those who sleep less.
159
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Termites work 24 hours per day and they do not sleep.
57
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
If you hold farts in during the day, they'll just come out when you sleep.
16