in undiggable places you need a terrier that will kill the fox, and get itself back out, no point in terrier baying away when your not going to get to it,it would be the owner that failed not the dog when the dog walked out,no dog can be expected to stay forever if you cant get to it,i would say a hard terrier for fox is easier dog to get than a good digging dog that needs to stay till you can get to it,it takes a lot of work to build a dogs confidence and turn it into a good dog and knolage of using the right dog in the right place helps the dog,anybody could make a dog from any line jack ,i