Stink bugs, common household pests, often prompt questions about their behavior as colder weather arrives. These insects, recognizable by their shield-shaped bodies, are frequently encountered indoors during the autumn and winter months. Their presence often leads people to wonder how they survive the cold and if they truly hibernate.
The Winter State of Stink Bugs
Stink bugs do not truly hibernate in the way mammals do; instead, they enter a state called diapause. This is a period of arrested development and reduced metabolic activity. During diapause, adult stink bugs significantly slow their metabolism, and their feeding and reproductive activities cease. This physiological change helps them conserve energy and rely on stored fat reserves to endure the winter months.
Environmental cues primarily trigger diapause. Decreasing daylight hours and cooler temperatures in late summer and early fall signal to the stink bugs that winter is approaching. This ensures they enter diapause before extreme cold sets in, increasing their chances of survival. They remain in this dormant state until conditions become favorable again in the spring.
Finding Winter Shelter
As temperatures drop, stink bugs actively seek sheltered locations to overwinter. In natural environments, they commonly hide under rocks, in leaf litter, beneath tree bark, or inside hollow logs. These natural hideouts provide protection from freezing temperatures and predators.
Stink bugs also frequently seek refuge in man-made structures, including homes, sheds, and barns, because these offer warmth and protection. They gain entry through various small openings such as cracks and crevices around windows and doors, gaps in foundations, utility pipe openings, and tears in window screens. Once inside, their flat bodies allow them to squeeze into tight spaces like wall voids, attics, basements, and behind baseboards, where they remain inactive. Upon finding a suitable spot, they may release aggregation pheromones, chemical signals that attract other stink bugs to the same overwintering site.
Spring Awakening and Management
When spring arrives and temperatures begin to rise, stink bugs emerge from their diapause state and become active again. They will then attempt to leave their overwintering sites, often making their way into the living spaces of homes as they search for a way back outdoors.
For homeowners finding stink bugs indoors, gentle removal is recommended to avoid triggering their defensive odor. Instead of squashing them, bugs can be gently swept into a plastic bag, jar, or a bucket of soapy water. To prevent future indoor incursions, sealing entry points is effective. This includes caulking cracks around windows, doors, and foundations, repairing damaged screens, and installing door sweeps. Reducing outdoor lighting near entry points can also help, as stink bugs are attracted to light.