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
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
If you hold farts in during the day, they'll just come out when you sleep.
16
You can reschedule your sleeping pattern by not eating 12-16 hours before you want to be awake. Upon eating after this time period, your internal clock will reset to a new day, with the time of your first meal being interpreted as "morning".
11
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
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