Bats sleep 18-20 hours per day.
5
There's a love mattress that is specifically designed for couples who sleep on each other's arms.
12
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
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
Termites work 24 hours per day and they do not sleep.
57
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
"Dysania" is the state of finding it hard getting up out of bed in the morning.
33