47% of people have a nightmare at least once a month.
186
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
You forget 90% of your dreams.
256
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
"Dysania" is the state of finding it hard getting up out of bed in the morning.
33
Termites work 24 hours per day and they do not sleep.
57
The human brain is more active during sleep than during the day.
28