Sea otters hold hands while sleeping so they don’t drift away from each other.
104
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
Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
The strangers in your dreams are actually people that you've seen in real life.
50
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
You forget 90% of your dreams.
256
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