Bats sleep 18-20 hours per day.
5
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
15
The average cat sleeps about 2/3 of the day.
203
Those who get out of bed by 7am are more likely to be thinner and happier.
20
Lack of water is the #1 trigger of daytime fatigue.
148
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13