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
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
Honeybees never sleep.
276
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
The human brain is more active during sleep than during the day.
28
Lack of water is the #1 trigger of daytime fatigue.
148
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23