Boxelder bugs are recognized by their black bodies with red-orange markings. In fall they congregate in large numbers on the warm, sunny south and west sides of buildings, then work their way into wall voids and attics to overwinter — re-emerging indoors on warm days.
They don’t bite or damage the structure, but their numbers make them a major nuisance. The fix is a well-timed fall exterior treatment before they move in.
How to identify
- About 1/2 inch, black with red-orange lines
- Gather on sunny exterior walls in fall
- Slow-moving; cluster in large groups
Signs of an infestation
- Masses of bugs on south/west walls in autumn
- Bugs emerging indoors on warm winter days
- Reddish staining where they’re crushed
Risks & concerns
- Harmless — no bites or structural damage
- Major nuisance in large numbers; can stain surfaces
- Carcasses within wall voids, chimneys and attics can provide an attractive food source for other pests including cabinet beetles.
How we treat boxelder bugs
We apply a targeted exterior treatment to walls and entry points in the fall, before they move into wall voids, and seal gaps around the structure.
Frequently asked questions
Permanent control combines timing with sealing: a professional exterior treatment applied in late summer or early fall — before bugs move into wall voids — plus caulking gaps around windows, doors, and utility lines so next year’s generation can’t get in either.
Vacuum them up rather than crushing them, and empty the vacuum bag outdoors in a sealed bag. Indoor sprays offer only short-term relief — the lasting fix is sealing entry points and treating the exterior walls where they gather before the next season.
They’re seeking warmth and congregate on sunny south- and west-facing walls before squeezing into wall voids and attics to overwinter. Without a fall exterior treatment and sealed entry points, the same walls attract them again the following year. To them, your house looks like a rock formation and the doors and windows look like caves that'd make a great place to wait out the winter.
Boxelder Bugs control
Get rid of boxelder bugs for good
Call or text to find the best solution for your pest problem. Appointments are typically available within 24 hours.