Black Flag Foaming Wasp & Hornet Killer aerosol spray delivers a blanketing foam to kill wasps, hornets and yellow jackets by contact. Also use it to control carpenter ants, harvester ants mud daubers, scorpions, spiders (including black widow and brown recluse) and tent caterpillars. The foaming jet spray shoots a powerful stream up 20 feet for fast knockdown, so you can treat nests above ground from a distance. To control stinging insects, apply to the nest outdoors at sunset, when insects are less active. Spray with the wind at your back. Stand up to 20 feet away from the nest, then aim and begin spraying while slowly walking toward the nest. Treat until the nest is soaked. Wait at least 24 hours before removing the nest. Remember, treat the nest – do not target individual wasps, hornets, mud daubers or yellow jackets. This formula leaves no oily residue and is non-staining to most home siding, depending on age and cleanliness, test in an inconspicuous area and check in a few hours.