At first, you wonder why your house cat seems to be so transfixed with the wall. Has it seen a ghost? But then the scratching and scraping sounds get loud enough that you can hear them. There's a long list of rodents and insects that can get into the walls of a house, and one of the most dreaded pests to do so is the wasp.
How They Get In
Wasps usually make their way inside the same way other pests do: through small holes in siding or foundation elements. The yellow jacket is the most likely type of wasp to put down stakes in a wall void. This kind of wasp usually nests underground but is also found in walls, attics and behind siding. Other wasps, such as paper wasps, typically build their nests outside of the building, such as on an eave.
Yellow jackets are:
- Black with jagged bands of bright yellow.
- Stocky-bodied with a short, narrowed waist.
- About 1/2-inches long; queens are longer.
The yellow jacket nest gets started in the spring by a queen. Once started, it'll continue to be added onto and will grow through the summer and into late fall. If left unchecked, the nest can expand to fill several wall voids. As worker bees travel within the wall to take care of young and build up the nest, you'll be able to hear scratching, buzzing and tapping from within the wall.
Don't Agitate Yellow Jackets
All wasps can deliver a painful sting that's dangerous to anyone who's allergic to them. Yellow jackets are especially problematic because when agitated or injured, they emit a scent that signals other yellow jackets to coordinate a persistent attack on their victim. That's why removal of this type of wasp infestation is best left to a professional pest control company.
Doing Nothing Can Be the Best Way to Handle It
If the yellow jacket nest is left undisturbed, it will remain active for only one summer, after which the queen will depart to start a new colony. The remaining wasps die off at the end of the season, and the nest is abandoned and never reused. So for this reason, it might make sense just to wait it out if you can. You can install hanging yellow jacket traps to help keep their numbers down in the meantime.
How to Get Rid of Them
When the nest is in a location that poses an unacceptable risk, steps can be taken to exterminate the yellow jackets. This usually doesn't involve completely opening up the wall, but rather a pest control worker drills small holes in the wall and injects insecticide dust into the wall cavity. To prevent yellow jackets from nesting in the home to begin with, make sure to seal up any possible entry points.