Dolphins have names for one another.
18
One litter of kittens can be produced by more than one father.
57
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81
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