Cows can sleep standing up, but they can only dream lying down.
745
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
You burn more calories sleeping than you do watching television.
348
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
47% of people have a nightmare at least once a month.
186
Bats sleep 18-20 hours per day.
5
Lack of water is the #1 trigger of daytime fatigue.
148