Why Don't Any Animals Have Green Fur?

Having green fur might seem like a real missed opportunity for the animal kingdom - it would allow animals to hide from predators, or surprise prey. So why have no animals evolved green fur?

Well, the first reason is that green is very hard for nature to make. Even frogs aren't truly green. They have blue crystals beneath yellow cells, and when blue light reflects off the crystals through the yellow cells, all colours are filtered out except green.

The second reason is that most animals are red-green colorblind, and so don't see colours the same way we do. In fact, most animals will see reds and greens as just different shades yellow or beige. This actually means that a browny coloured animal is just as well camouflaged as a green coloured animal!

So, there is no advantage of having green fur over red fur for most animals.