These mousetraps are very effective. You just put a tiny amount of peanut butter in the little pot, insert from underneath and pull back to set. I heard one go, with some scrambling legs on the floor for maybe 2-3 seconds at most, then quiet. There is no blood to clean up, it looks like a very quick kill breaking the neck. None of this trapping a limb with a slow death and blood everywhere like the old style snap-traps sometimes do. I've not had any false snaps either, and they are easy to pick up and decommision without trapping fingers.