Cows can sleep standing up, but they can only dream lying down.
745
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Dieters who sleep more take off more fat that those who sleep less.
159
Bats sleep 18-20 hours per day.
5
Sleeping on the job is acceptable in Japan. It is viewed as exhaustion from working hard. Some people fake it to look committed to their job.
57