The brown marmorated stink bug is the main species responsible for home invasions as temperatures drop. The answer to whether these insects disappear in the winter is no; they simply relocate to survive the cold. These pests actively seek sheltered spaces inside human-made structures to enter a survival state until spring returns. This means they are dormant within the walls and voids of a house.
The Overwintering Phase (Diapause)
The biological mechanism driving the stink bug’s winter survival is called diapause, a state of insect dormancy triggered by environmental cues like shorter daylight hours. This mandatory stage allows adults to survive periods when food is scarce and temperatures are too low for activity. During diapause, the bugs do not feed, and their reproductive development is temporarily arrested.
Stink bugs are chill-intolerant and would die if exposed to prolonged freezing temperatures, making the warmth of a building necessary for survival. Diapause is triggered when the length of daylight drops below a critical number of hours. They wait out the cold in a state of metabolic suppression, conserving energy until conditions improve.
To find suitable shelter, the bugs aggregate on sun-warmed sides of structures during the fall, attracted by aggregation pheromones. Once inside, they move into secluded, dry areas such as attics, basements, and wall voids. Other common overwintering spots include spaces behind baseboards, under insulation, and around window and door moldings.
Seasonal Timing of Stink Bug Activity
Stink bugs move into homes during the fall aggregation period, typically from late September through October, as outdoor temperatures cool. They search for protected overwintering sites, often gathering in large numbers on the exterior before finding tiny crevices to enter.
The overwintering period lasts until spring emergence, which usually takes place between March and May. The bugs become active and leave the structure to resume feeding and reproduction outdoors. This movement is driven by the insect’s biological clock signaling the end of diapause.
Homeowners may see premature emergence inside during the winter, usually due to the home’s heating system or a temporary warm spell. Elevated indoor temperatures can “trick” the dormant bugs into thinking spring has arrived, causing them to move out of hiding spots and into living spaces while seeking an exit point.
Homeowner Prevention Strategies
The most effective way to manage these pests is through exclusion, which involves sealing all potential entry points into the home before the fall aggregation period begins. This prevention work should be completed in late summer or early fall. A thorough inspection of the building exterior is required to find all possible access points.
High-quality silicone or silicone-latex caulk should be used to seal any openings small enough for the flat-bodied insects to enter. Specific areas to seal include:
- Cracks and gaps around window frames and door jambs.
- Openings around utility pipes and under the wood fascia.
- Damaged or torn window and door screens, which must be repaired or replaced.
- Gaps around doors, where weatherstripping should be installed.
If bugs are found inside, safe removal is preferred, as crushing them releases the strong, unpleasant odor that gives them their name. A vacuum cleaner can be used to remove large numbers of bugs. Inserting a knee-high stocking into the vacuum tube can prevent the odor from permeating the machine. The collected bugs can then be emptied into a container of soapy water for disposal.