Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
13
When dragonflies mate, their tails form a love heart.
22
There's a young hippo and a 130+ year old tortoise in a Kenyan wildlife preserve who are best friends and they even sleep and play together.
40
Dolphins have names for one another.
18
One litter of kittens can be produced by more than one father.
57