One reason that kittens sleep so much is because a growth hormone is released only during sleep.
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People who sleep late have more mental stamina and can outperform early risers.
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Termites work 24 hours per day and they do not sleep.
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Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
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The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
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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