Why Yellow Color Most of the pests have phototaxis, and yellow is the favorite color of common pests like aphids, leaf miner, fungus gnats, thrips, white flies, black flies, fruit flies, midges and so on, with this Trapro yellow sticky trap, pests just can not control themselves and keep flying towards it. ECO Friendly 100% made from non-toxic material, high and low temperature resistant and waterproof, controlling pests in a more Eco friendly and economical way, ideal for garden, farm and greenhouse use. How to use For trees or other large plants: Use the included wires to hang the yellow stick traps on the branches; For small plants: Place the yellow sticky board tightly on a stick, and insert it into the underground. Recommended using denisty For best performance, we recommend an using denisty of 1pcs/200 square feet or 200pcs/1 acre. Kindly note If touch the adhesive accidentally, just wash your hands with some vegetable oil or waterless hand cleaner.