I used this foil tape to keep slugs away from my potted plants. The liquid secreted by the snail's body reacts to copper in the same way as it does to salt. The ongoing electrolysis prevents them from crossing that line. However, the width of this tape, which is approximately 1/8 inch, is not sufficient on its own. I had to wrap a few rows around the rim of my pots to create a strip about half an inch wide to give him enough time to react to the amount of her body that came in contact with it or they would over that 1/ 8 slip inch pieces. Duct tape and never feel it.