I have two 6 month old kittens who've just started going outside (daytime only, door always left open) I can see a fox on a wall three gardens away; there's a couple of very overgrown gardens, and I see a fox pass by regularly. I don't know how danger-aware the kittens are, or indeed how dangerous foxes are to cats - can anyone give me some advice? They're rescue kittens who left their mother at 8-10 weeks, if that makes any difference.