Dolphins have names for one another.
18
Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
13
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
Sea otters hold hands while sleeping so they don’t drift away from each other.
104