Never used one as a kid as I couldn’t afford one and had to sit around for hours waiting for it to come out . Some people say a ferret that stays is no good ,,, I say bollox to that, a ferrets job is to go down scare rabbits out and if they won’t leave then kill them and Then you break through and remove ferret, if a ferret kills a rabbit first set you get to then decided have a good feed you could potentially be waiting couple hour for it to feed sleep then decide have nosey around ,, and all this could be happening 12 inch under your foot and without a ferret locater you’ll never no ,