Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
13
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
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
Dolphins have names for one another.
18