Wilko wasp nest killer foam 300ml is an insecticidal foaming spray designed to kill wasps in their nests for best results apply late evening or early morning when the wasps are less active contains sufficient foam for around 2 3 treatmentswarningvery toxic to aquatic organisms extremely flammable aerosol keep out of reach of children always read instructions before use contains 027 ww permethrin and 011 ww tetramethrin