One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
Lack of water is the #1 trigger of daytime fatigue.
148
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
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
If you hold farts in during the day, they'll just come out when you sleep.
16