I watched a couple of videos on Youtube showing how to make a leech trap out of pie tins or aluminum foil pans. I wish I knew of a pond with leeches in it to give it a try. Just fold the pans in half, poke some 3/8 dia hole in it, clamp it to together with 4 binder clips with some meat/fish guts and weight inside. Tie some heavy line to it and throw it in a pond. Check it early the next morning and remove the leeches. looked simple, probably won't work.