I made a trap to get mine out. I took a water bottle cut the top of it off, so you will end up a funnel. Cut some small holes into the lower part of the bottle (so it will sink when in the water). I then took the upper part (the funnel) inverted it and glued it to the lower part of the bottle. Let dry, put a good sized piece of food in the bottle for bait. Place the bottle on the bottom of the tank and wait. I had better luck catching them this way after the lights where out, because the fish would also try and get the food when the lights where on.