My back garden is adjacent to two others that are currently untended and covered in 50cm high grass, thistles and brambles. They clearly have paths though them that are not only regular byways, but spots for general jumping around and chasing one's own tail, which I took to have been made by foxes. In addition, every so often, the bin bags put out for the dustmen are totally savaged. I've never seen any of these foxes, but then I've only been here for two months. I did think of cats, but I haven't seen any around here, there's a healthy bird population, and they don't bother to hide in the day. Besides, the paths seem to wide for cats.
Here's the thing though: I've just found what I take to be fox cr@p on my lawn, but there isn't an obvious access point for a fox at ground level. The only way in is to climb or jump over a 1m50 wooden fence. Can foxes get over that? The tracks are mostly in the garden that abuts a wire fence which makes sense, but there appear to be occasional forays into the two other gardens.