A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Bats sleep 18-20 hours per day.
5
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
You can reschedule your sleeping pattern by not eating 12-16 hours before you want to be awake. Upon eating after this time period, your internal clock will reset to a new day, with the time of your first meal being interpreted as "morning".
11
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
You forget 90% of your dreams.
256