A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Cows can sleep standing up, but they can only dream lying down.
745
People who sleep late have more mental stamina and can outperform early risers.
33
"Dysania" is the state of finding it hard getting up out of bed in the morning.
33
Honeybees never sleep.
276
The human brain is more active during sleep than during the day.
28