why fox is the symbol of sly?

I don't think so the point about foxes as the symbol of sly, in my eyes foxes just use their instinct to survive, their are not the stronger group in animal's field, so this cannot look as sly.

I think your question is very interesting.I have never thought of the question.I think people endow with every animal different meanings for its life behaviour or its caracter.but i don't think fox is sly in real-life.When i only a child,the fairy tale tell me the fox is always sly.they cheat other animals.Most of people must have read Andersen fair tale and in his story,fox is also the symbol of sly. I really want to know why,If you know please tell me,thank you!

I'm not sure the real reason behind it but from what I've seen of foxes in my neighborhood, they are super sneaky and sly. They slink around at dusk, I've seen one sneak up and grab a neighbor's kitten. My neighbor was standing about two feet away. That fox snuck right up snatched the kitten and took off. My poor neighbor didn't knew what hit him. It was a horrible thing to watch. No one could do anything. All my neighbors got together and tried finding the fox and kitten but to no avail. So from my experience, foxes are very smart and sneaky.