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).
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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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If you hold farts in during the day, they'll just come out when you sleep.
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The average cat sleeps about 2/3 of the day.
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In China, teachers allow children to sleep in class for around 20 minutes to help improve their learning.
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A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
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