Honeybees never sleep.
276
If you hold farts in during the day, they'll just come out when you sleep.
16
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
People who sleep late have more mental stamina and can outperform early risers.
33
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240