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.
25
Ten seconds of hugging a day increases levels of oxytocin, which can reduce blood pressure, thus cutting the risk of heart disease.
26
Dolphins have names for one another.
18
Sea otters hold hands while sleeping so they don’t drift away from each other.
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