basically a box set in the ground, the top is flush with the earth, has a tunnel effect with a see saw bottom, its placed on a fence line, where rabbits pass through, left locked at first so rabbits get used to using it, then set, so as a rabbit runs through, it drops into the underground box, hence the name, numbers of rabbits can be caught, but as memtioned, to stay within the law this would need to be checked daily, also they can be quite expensive, so you wouldent want to place it, where some little scrott is going to nick it, thats my reason for saying it wont affect ferreting,