A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
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
Termites work 24 hours per day and they do not sleep.
57
The average cat sleeps about 2/3 of the day.
203
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Bats sleep 18-20 hours per day.
5