IMHO I have no problem with a ferret killing below ground if it then moves on, its up to me then to decide wether to dig or not, several times ferreters on these sites say they work their ferrets without collars because their ferret always comes out(ask the working terrier lads how long they would keep a terrier doing this, or a lurcher pulling up in view of game?)I expect a good ferret to kill and move on or stay until I've dug to it if it has nt killed but is trying its best to kill the rabbit. not all ferrets will achieve this expectation so I dont breed from them if they dont, BEST WORKER