There's a love mattress that is specifically designed for couples who sleep on each other's arms.
12
The human brain is more active during sleep than during the day.
28
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
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193