You don’t forget the first time you hear it, and you can’t just forget about it. There is something in your wall or ceiling and it is scratching, clawing, or chewing. What could it be? In this series of the DIY Pest Controller, we will explore the most common causes and solutions to a scratching sound in your wall or ceiling.
I have occasionally received a service call request to treat for rodents in a home. The homeowner will state that they “all of a sudden” started hearing a scratching or chewing sound in the wall or ceiling. If there is an attic above the ceiling, we can eliminate some possible causes of the sounds. If no animal droppings are seen in the attic, or if the insulation does not look disturbed by rodents (or something larger), then it’s time to start thinking that the sound is insect related.
If the sound is coming from a wall, simply place your ear to the wall and listen to the sound. If the sound sounds like wings flapping, the issue is typically a bird or bat. A bird or bat trapped in a wall is more typical in older homes where the wall voids are greater. Refer to our series on animals in your home for more information.
There are 2 types of insects that will make noise like chewing or scratching and should be treated. The first is a yellow jacket nest, which we will cover in this article, the second is carpenter ants, which will be covered in our next article in this series. To verify if you have yellow jackets or carpenter ants making the sound, go outside and look around the area where you have been hearing the sound on the inside. If you see a lot of yellow jackets flying around that area or see them coming and going from your home, you have a nest in the house.
Once you have verified that you have a yellow jacket nest in the wall or ceiling, it is time to treat the nest and remove it. If the nest is allowed to continue, it will very quickly grow and wear away at the drywall in-between you and the nest. Often times, I can put my finger easily through the wall or ceiling drywall because the moisture in the nest has made the drywall paper-thin. You will want to use an approved aerosol insecticide that is labeled for use on yellow jackets and wasps. Make sure you have at least 2 cans because once you start the treatment, you shouldn’t stop until the treatment is complete. The last thing you want is to begin applying the insecticide and run out, allowing the still alive yellow jackets to pour out of the nest and voice their displeasure with your actions.
- Drill or poke a small hole in the drywall directly over the nest (where you suspect the nest is).
- Apply the approved aerosol insecticide in a manner that is in compliance with its stated label
- Continue to apply the insecticide until you are confident that it has permeated the wall or ceiling void.
- Once all of the yellow jackets are no longer a threat, it is time to remove the nest. Removal of the nest is critical to prevent future infestations
- If the drywall is super soft and thin, remove that entire section since it will need to be replaced anyways. Otherwise, cut a section out so that you can access and remove all of the nest material
- Apply an insecticidal dust into the void, making sure that the product that you use is labeled to do so. This will prevent the bees that were not in the nest from entering the former nesting area.
- Caulk or seal up the gap on the outside where the bees were entering the house.
After the nest has been treated, removed, and the entrance sealed up, temporarily close up the drywall area that you cut open. This will prevent any straggler bees from entering the livable space of your home. You can use a simple barrier of cardboard and tape until you can get the drywall patched and repaired.
A final word of caution:
Yellow jackets are not like honey bees. They are aggressive, stinging insects that love to defend their home. If you or someone in your home is allergic to bee stings, this may not be the project to tackle yourself. Once the treatment begins, there is no going back. Hire a professional if you think that this may be outside of your comfort level.