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
Sea otters hold hands while sleeping so they don’t drift away from each other.
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The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
You burn more calories sleeping than you do watching television.
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Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
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