You forget 90% of your dreams.
256
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
Bats sleep 18-20 hours per day.
5
One reason that kittens sleep so much is because a growth hormone is released only during sleep.
212
The human brain is more active during sleep than during the day.
28
Termites work 24 hours per day and they do not sleep.
57
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