The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
Termites work 24 hours per day and they do not sleep.
57
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