Wasp Nest Removal
Summary: Removing a wasp once the wasps have died should be done as soon as possible. The leftover nest may contain dead insects or stored food that will decay. Once it begins to decay you will be fighting mold and other invading insects.
Sam S; Vancouver, British Columbia asks: I had a wasp nest inside my living room wall. I heard buzzing in the walls and treated the spot with a spray insecticide. Now, there is a strong, "musty" odor coming from a section of the living room wall exactly where I heard the buzzing. Do wasps nests have an odor or is it possible I now have a mold problem?
Dear Sam: Yes, you could have a mold problem inside the wall. That's why we never suggest treating wall voids with liquid sprays. A professional exterminator attempting a wasp nest removal would or should only use pesticide dusts to treat inside walls.
Remember, the wasp nest, which could have contained hundreds or even thousands of larvae, has had the attending adults killed. The larvae have died and are rotting inside the wall and are probably the cause of what you are smelling.
It didn't help matters when you introduced liquid pesticide into the walls. The space inside walls are supposed to remain dry. The liquid sits there creating a wet environment and suddenly the development of mold becomes a real possibility.
We always recommend opening a wall to remove the nest after the wasps or bees have been eliminated. Now you can kill two birds with one stone. Open the wall to remove the dead nest and remove any materials that have mold caused by the moisture you injected.