Stink bugs invade homes in cold weather because they're hunting for a warm, sheltered place to wait out winter. The brown marmorated stink bug, now common across Southwest Michigan, slips through gaps in siding, windows, and rooflines in fall and clusters inside walls and attics until spring.
You know it’s “that time of the year” when the stink bugs show up on your house at every single window and door. It’s seasonal behavior and not so much an “infestation” the way the word is used by the experts. It’s still a hassle, though.
The stink bugs are looking for shelter. Your home qualifies. The brown marmorated stink bug isn't native here. It arrived from Asia, spread through the region, and became both a farm pest in the fruit belt and a household nuisance. As fall temperatures drop, it enters a dormant overwintering state and starts searching for a protected spot to ride out the cold. In nature, that might mean a rock crevice or a hollow tree. On your property, that means your heated home.
You'll often notice them gathering on the warm, sunny side of the house first, usually the south or west walls in the afternoon. From there they work into the smallest openings: gaps around window frames, cracks in siding, spaces where utility lines enter, torn screens, and unsealed soffits. Once they make their way inside the wall voids and attic, they settle in and go quiet.
They don’t bite. They don’t breed indoors. And unlike termites or carpenter ants, they won’t tear up your house. But they smell awful when you crush them, so you don’t want them around. On warm winter days or in early spring, some wake up and wander into living spaces, turning up at windows and lights.
The best way to deal with stink bugs is to keep them from entering. You can do this by sealing cracks, caulking around windows and utility lines, and repairing screens in late summer on doors and windows. You can also have an exterior perimeter treatment done in early fall before they migrate so you can intercept them before they crowd your walls. It’s important to move early, though, because once they settle into the walls, your options are limited.
If you're tired of stink bugs taking over your windows every cold season, Mosquito Squad of Southwest and South Central Michigan can help. This can be done through perimeter treatments that help control stink bugs and other overwintering pests before they get inside, applied by a trained technician, alongside the seasonal barrier service that delivers up to 90% reduction in mosquito activity on a 21-day cycle.
