When trimming my hedges, I discovered an underground wasp nest. These wasps were really aggressive and dangerous. After I ran away and they calmed down a bit, I used a Gotcha Sprayer Pro and Powder Duster combination attached to an 18ft extension pole to dust the nest. I used Diatomaceous Earth to do the dusting. DE is made of crushed sea shells, so it's safe to use. It doesn't work right away, but the next day the nest was completely empty. Dusting while Standing 18ft away from the nest was also very helpful.