In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
Lack of water is the #1 trigger of daytime fatigue.
148
Bats sleep 18-20 hours per day.
5