Still Seeing Asian Lady Beetles, Box Elder Bugs, Stink Bugs, and Even Wasps in January?

Let's talk about why they're still in your home and what you can and can’t do about it.

If you're noticing a sudden appearance of lady beetles, box elder bugs, stink bugs (Western Conifer Seed bug), or even wasps inside your home this January, it's easy to assume you have a new pest problem. However, it's important to correct a common misconception: you are not experiencing a new invasion. The invasion already happened—most likely in late October or early November.

Asian lady beetles and similar insects are extremely predictable in their overwintering behavior. Here is how the process works.

The Fall Invasion: It Happened Months Ago

The mass migration to overwintering sites is triggered by a specific weather combination:

1. A Freeze Event: You typically get a frost or near-freeze event in the fall.

2. A Warm-Up: After the freeze, temperatures recover to around 64°F, or even 61–62°F on a sunny day.

This combination of cool nights followed by warm, sunny afternoons is the signal. When this happens, the insects perform a mass migration, and that is when homes get invaded as they seek protected void spaces, walls, and soffits to spend the winter. What's Happening Now: Purgatory

What you are seeing now, in January, is entirely different. During winter warm-ups, when ambient temperatures hit 50–60°F combined with strong sun, your home’s walls, soffits, and void spaces heat up. The warmth pulls the hidden beetles out of diapause (a state of arrested development).

Once active, their instinct is to follow the warmest air path, believing it will lead them back outside into spring-like conditions. Unfortunately, that warmest air path currently leads into the home, not out of it.

Once inside, they are drawn toward UV light, which is why they collect at windows. At this point, they are effectively stuck. The home does not get cold enough for them to re-enter diapause, but it is also not warm enough for normal activity or escape. They are in a state I call “purgatory.” Eventually, they die indoors.

What Can Be Done Now (Realistic Expectations)

At this stage, expectations need to be realistic. There is no true “elimination” option once overwintering insects are already inside a structure.

That said, there are a few tools that can help reduce activity and visibility:

• Mechanical Removal (HEPA Vacuum): This is considered the correct treatment once these insects have entered a structure. It safely removes them without crushing them and causing a defensive odor (especially with stink bugs and lady beetles).

• Insect Light Traps (ILTs): These can be very effective as they intercept the insects before you ever notice them flying or crawling around your living spaces.

• Glue Boards on Windows: While not attractive, they are highly effective. The insects move toward the light, where the boards trap them. They often outperform residual insecticides indoors.

• Target UV-Attraction Points: Light treatment around windows and doors, which naturally emit UV light, can help reduce the congregation of insects in these visible areas.

• Crack and Crevice Treatments: These may help limit beetles emerging from wall voids, attics, or crawlspaces, but results are inconsistent once the insects are already past the main structure envelope.

The Real Fix: Timing is Everything

The definitive way to control these insects is to prevent their entry before they enter the structure. That window of opportunity is August, September, and October.

If your home is known to be highly prone to overwintering insects, make sure your exterior residual treatments are not more than 30 days old when the fall mass migration begins. Proper timing and exterior exclusion are the only ways to prevent January problems—you can't chase the beetles once they are already inside.

Schedule Your Fall Prevention Service Now