A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
47% of people have a nightmare at least once a month.
186
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
Bats sleep 18-20 hours per day.
5
A new parent will lose about 1055.6 hours of sleep in the first year of their child's life - almost 44 days!
6