Bats sleep 18-20 hours per day.
5
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
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
You burn more calories sleeping than you do watching television.
348
The human brain is more active during sleep than during the day.
28
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
If you hold farts in during the day, they'll just come out when you sleep.
16