Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
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When a male gentoo penguin "falls in love" with a female penguin, he searches the entire beach to find the perfect pebble to present to her.
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One litter of kittens can be produced by more than one father.
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Squirrels will sometimes adopt orphaned baby squirrels that they’re related to.
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Ten seconds of hugging a day increases levels of oxytocin, which can reduce blood pressure, thus cutting the risk of heart disease.
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