Brown marmorated stink bugs arrived in the United States in the late 1990s, likely from Asia via shipping containers, and have spread to most of the country including Oklahoma. By late September in the OKC metro, homeowners start finding them on south-facing walls soaking up warmth, and shortly after that, inside the house. A single individual is a minor annoyance. A wall void full of them overwintering is a different matter. Understanding why they come in and blocking the routes they use is the practical approach.
Quick answer
Brown marmorated stink bugs enter Oklahoma City homes in late September and October looking for overwintering sites. They squeeze through gaps in window frames, door thresholds, utility penetrations, and siding seams. They do not breed indoors, bite, or cause structural damage, but they emit a sharp odor when crushed or disturbed. Sealing entry points before fall is the most effective prevention; vacuuming up individuals is the standard interior control.
Dealing with this right now?
Getting a stink bug influx every fall in your OKC home? Acenitec offers exterior perimeter treatments timed for late summer that reduce the number making it inside. Call before the September migration starts.
See how our general pest control service works around the OKC metro.
What Stink Bugs Are and Are Not
The brown marmorated stink bug is about three-quarters of an inch long, shield-shaped, and mottled brown with alternating light and dark bands on the edges of the abdomen. It is not a beetle. It belongs to the true bug order Hemiptera and has a piercing-sucking mouthpart used on plants, not people.
Stink bugs do not bite, do not damage wood or fabric, do not breed indoors, and are not dangerous to people or pets. The only issue they create indoors is odor when disturbed. The gland that produces the smell is on the underside of the thorax. Crushing one releases it, as does disturbing a large group in a wall void.
Why They Come Inside in Fall
Stink bugs are warm-season insects that overwinter as adults in protected sheltered sites. As daylight shortens and temperatures drop in September and October, they begin seeking sites to wait out the winter. South- and west-facing walls that absorb afternoon heat are gathering points before they find their way through gaps into the structure. They use aggregation pheromones, meaning where one enters successfully, others follow.
Once inside a wall void or attic, they enter a low-activity state but do not hibernate completely. Warm days in late winter and early spring cause them to become active again, and they begin moving toward light, which is when homeowners find them on windowsills and in light fixtures.
Where They Enter Your Home
Stink bugs are remarkably good at finding gaps. Common entry points include the gap between a window frame and the siding, the junction of a brick veneer and the wood frame, weep holes in brick, gaps around pipe penetrations through exterior walls, attic vents without fine screening, and door bottom gaps. They can pass through a gap as small as a quarter inch.
An entry-point audit before September is the single most effective thing you can do. Walk the exterior of the house looking for any gap where the siding meets a window frame, door frame, or utility penetration. Fill gaps with a quality exterior caulk and replace torn or damaged window screens and door sweeps.
- Gaps around window and door frames where caulk has cracked or failed
- Weep holes in brick veneer (can be screened with open-cell foam)
- Attic soffit vents without fine mesh
- Gaps around utility lines, pipes, and cable penetrations
- Door sweeps that are worn or not making full contact with the threshold
If They Are Already Inside
Vacuuming stink bugs up individually is the most reliable interior control. Use a bag vacuum rather than bagless, and seal the bag in a plastic bag immediately after. You can also place a damp towel over the vacuum inlet to knock them down before they die and release odor. Avoid using your best vacuum for this task repeatedly.
Residual insecticide treatments applied to the exterior perimeter in September, before stink bugs aggregate, reduce the number making it inside. Interior treatments in wall voids are generally not recommended; they kill bugs that then attract other pests feeding on insect material inside walls.