Permanent Wasp Foam is intended for the control of wasps and their nests as well as other insects from hard-to-reach cavities or other difficult places. Spray the foam late in the evening or early in the morning, especially into the nest opening and if possible directly into the opening, so that the foam also spreads to the cavities inside the nest. If the wasps dig out through the foam, repeat the treatment. Use biocides safely. Always read the labels and product information before use.