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
Dolphins have names for one another.
18
A group of kittens is called a "kindle".
10
When cats are happy, they may squeeze their eyes shut.
10
Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
13