Lack of water is the #1 trigger of daytime fatigue.
148
Studies show that the colder the room you sleep in, the more likely you are to have a bad dream.
28
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
A new baby usually deprives each of it's parents around 350-400 hours of sleep in the first year. That is one entire nights sleep per week, per parent.
194
Honeybees never sleep.
276