This depends on both the plant and the type of pest you are dealing with. For small plants or fungus gnat infestations, stick the trap straight into the potting soil using one of the enclosed metal trap holders. For larger plants or whitefly infestations, hang the traps on the plant using the enclosed wire. Gently shaking the plants on a regular basis will disturb the pests and encourage them to fly towards the trap. Caution: Yellow sticky traps can also stick to your pets’ fur, so keep this in mind when placing them.