cornergran I believe putting small holly branches or something prickly on the bare soil stops them, as they will not squat down where they are. I wanted to try that, but we don't have any prickly shrubs I could cut, which is why I tried the canes. As I said, they work, and it has stopped them coming into the back garden. They are now using the front garden, but we are going to completely redesign that soon, so I am not too bothered with that.
I read on the internet that a short length of garden hose, curled round, on the lawn deters them as they think it is a snake. We have not tried this. We did try the device that emits a high pitched noise. They used to saunter past it, with smirks on their faces!