Planaria trap comes with 3 holes design which is able to trap planaria efficiently to reduce planaria population in tank. Planaria trapped inside the tube will never able to come out from the designed hole. Trap/Catches Planaria, Flat Worms and Leeches. Put in bait such as raw pork liver, dead fish, shrimp, meat, etc, then fill the trap with water and place it with holes facing down soil bed. Switch off lighting during planaria trapping.