Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
Cats and dogs can hear ultrasound.
350
Cymothoa exigua is a type of parasite that enters through fish's gills, eats their tongue, and then replaces it.
6
There is a sea snail that wears a suit of iron plated armor. It is the only known animal to use iron sulphide as skeletal material.
9
When Washoe, the first chimp to use sign language, was told that her caretaker's baby had died, she signed "CRY."
20
When you shave a guinea pig it looks like a little hippo.
19
There was a bear called Wojtek who was adopted by Polish soldiers during WW2. It carried ammunition, wrestled with soldiers, and drank beer.
40