Thanks Jan will have to try that.  There are up to 6 foxes and they have already burrowed under my fence into next doors garden but they don't stay in there.  They have burrowed under the compost heap and live there.  Unfortunately my garden is rather overgrown at the moment as I spent a long time away looking after someone 24/7 and couldn't get home as it was too far.  Now I have the job of clearing it all and don't like being out there when the foxes are about as they come right up to the back door.  Whether they would attack I don't know but don't really want to find out either.  Just want them to go away.