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
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
There's a love mattress that is specifically designed for couples who sleep on each other's arms.
12
Honeybees never sleep.
276
In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
13
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193