Cows can sleep standing up, but they can only dream lying down.
745
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
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
You forget 90% of your dreams.
256
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
Sleeping on the job is acceptable in Japan. It is viewed as exhaustion from working hard. Some people fake it to look committed to their job.
57