A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29
Cows can sleep standing up, but they can only dream lying down.
745
A new parent will lose about 1055.6 hours of sleep in the first year of their child's life - almost 44 days!
6
People who sleep late have more mental stamina and can outperform early risers.
33
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
The average cat sleeps about 2/3 of the day.
203