Wirral, spot on. I would only add that I wouldnt describe the 'diggin' approach as traditional, its precisely the opposite actually, historically terriers were bred to BOLT qaurry. Fact. Obviously as you rightly say sometimes you had to dig and we had a few examples where, for instance, the fox was mid bolt saw or sensed us and returned to earth. In those circustances we probably ended up digging and even in those cases my dog would keep harassing the fox so it either stayed put or was forced to bolt again. An ability to mark properly, find a fox below ground and follow is what an earth dog sh