Concealed Nests

The most challenging wasp nests to control are those that are concealed in voids behind walls or in attics. Often, the only evidence of the nest is wasps flying back and forth through a crack or hole in the home.
Aerosol insecticides usually do not work very well against hidden nests. The best method is to apply a small amount of insecticidal dust or drill small (about 1/8 inch) holes to deliver the insecticide into the nest area.
When treating wasp nests hidden in building voids, we may use the following insecticide dusts:
- bendiocarb
- chlorpyrifos
- boric acid (will be slow acting)