Cows can sleep standing up, but they can only dream lying down.
745
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
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
Lack of water is the #1 trigger of daytime fatigue.
148
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Honeybees never sleep.
276