Hi simbo65,
Yes, I would leave some water in the feeding box as well if there is room. They are terrors at tipping the water over! If you can, try to get a dish with a flat bottom and shallow straight sides, that way they are less likely to tip it over. They will still probably walk through it though!
I thought cats were bad enough at getting into feed boxes. Never heard of a fox getting in one before! It is best to have a tunnel, either internal with ‘baffles’ or external to help avoid unwanted ‘guests’ – as you have done. Let’s hope the fox stays away.
