Wasps and hornets can be dangerous nuisances during the summer months, but there are many insecticides designed to kill these creatures before they sting you or your loved ones. Before attempting to destroy a wasp or hornet nest, it is crucial that you wear proper clothing, preferably a wasp suit with cinched ankles, wrists and neck. At minimum, thoroughly cover your face, hands and body. If you are uncomfortable performing these measures on your own, call a qualified pest control specialist.
Exposed Wasp Nests
If you can see wasp nests near places where your family and friends congregate and could be stung, apply a basic wasp and hornet spray found at hardware stores that contains a combination of tetramethrin and D-phenothrin. Wait until the sun goes down and the wasps have gone inside their nest, then use a red-beamed flashlight for light, as wasps are not sensitive to red light. Stand several feet away from the nest and spray the product onto all surfaces of the nest until it is thoroughly covered. If wasps do not appear the next day, you have successfully killed them. If they do appear, continue to apply the product every 3 days until they are gone.
Ground Wasp Nests
Ground wasps, also known as yellowjackets, require different protocol and pesticides than other wasps. A first effective plan of action is to wait until it is dark outside and, using a red-beamed flashlight for light, pour a solution of soapy water into the entrance of the nest. If ground wasps still appear one day after using the solution, apply a dust product that contains either carbaryl or chlorpyifos, as dusts are more likely than liquids to penetrate the nest. Insert the applicator into the nest entrance and inject several puffs of dust. Once wasps are dead, cover the entrance to the nest with soil.
Hidden Wasp Nests
Wasp nests hidden inside walls or attics can be difficult to destroy, as aerosol insecticides are ineffective in this situation. Apply an insecticidal dust that contains bendiocarb or chlorpyrifos, comes with an applicator, and is labeled for use in homes. After dark, and using a red-beamed flashlight, insert the applicator into the nest entrance and expel the product into the opening several times. Once all wasps are dead, seal the nest by filling the entrance with caulk to prevent future wasps from reinhabiting.
Destroying hornets' nests is much more dangerous than wasp nests, as hornets are more aggressive. It is best to hire a professional if you are not experienced. For visible nests, you may follow the exposed wasp nest instructions described above if you are comfortable doing so. Before beginning, put on a full wasp suit with sealed wrists, ankles and collar. Apply the insecticide as described, inserting the applicator into the opening at the bottom of the nest. Avoid breaking open the nest during application, and only use the bottom opening. Wait one day to inspect the nest. If hornets are gone, the nest can be taken down and thrown out. If they are not, repeat the process.