A few years back I owned a dog ferret which killed nearly every time we used him, lucky for us most of our setts are only a spade blade deep mainly grassland grazed by sheep nice soft soil, he would kill so often and so quickly we would follow him with the bleeper and as soon as he stoped mark the spot with a stoneone of us dig and the other follow him with the box, in places where we had alot of rabbits and at the begining of the season we would often get 3 or 4 rabbits like this in one set, how ever this ferret is now dead and although we bred from him none of the ofspring have been as good