In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
Dieters who sleep more take off more fat that those who sleep less.
159
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The human brain is more active during sleep than during the day.
28
There's a love mattress that is specifically designed for couples who sleep on each other's arms.
12
Termites work 24 hours per day and they do not sleep.
57
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Honeybees never sleep.
276