Traps I used made of plastic did not last long because when trapped the mice gnawed through the plastic retaining clip so that it could not be used again. These are metal so this cannot happen. However the traps kept being robbed and I had to use pliers to bend round the bait holding spike to allow the bait to be held better. I would like to see them improved with a sensitive hinged plate round the bait similar to those on the plastic traps that the mice trigger when they tread on the plate.