The human brain is more active during sleep than during the day.
28
The average cat sleeps about 2/3 of the day.
203
People who sleep late have more mental stamina and can outperform early risers.
33
Those who get out of bed by 7am are more likely to be thinner and happier.
20
Bats sleep 18-20 hours per day.
5
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23