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
47% of people have a nightmare at least once a month.
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People who sleep late have more mental stamina and can outperform early risers.
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The average cat sleeps about 2/3 of the day.
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There's a love mattress that is specifically designed for couples who sleep on each other's arms.
12
Sea otters hold hands while sleeping so they don’t drift away from each other.
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