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
"Dysania" is the state of finding it hard getting up out of bed in the morning.
33
The human brain is more active during sleep than during the day.
28
You burn more calories sleeping than you do watching television.
348
Bats sleep 18-20 hours per day.
5