A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The average cat sleeps about 2/3 of the day.
203
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
47% of people have a nightmare at least once a month.
186
Dieters who sleep more take off more fat that those who sleep less.
159