Stink bugs, a common nuisance, survive winter by seeking indoor shelter as autumn arrives. They employ specific biological strategies to endure cold temperatures.
Their Winter Survival Strategy
Stink bugs survive the cold by entering a physiological state known as diapause, which is similar to, but distinct from, hibernation. During diapause, their metabolic activity significantly slows down, and they cease feeding and reproducing. This arrested development allows them to conserve energy and persist through harsh conditions.
Their bodies undergo changes for this dormant period. They reduce internal water content and increase cryoprotectants like glycerol in their bodily fluids. Glycerol acts as a natural antifreeze, preventing ice crystals from forming within cells and tissues, protecting them from freezing damage.
Where They Seek Shelter
As outdoor temperatures decline in the fall, adult stink bugs actively search for protected locations to overwinter. They are drawn to warm, secluded spaces, often congregating in large numbers. Many species, particularly the brown marmorated stink bug, frequently invade human structures for this purpose.
Common overwintering spots inside homes include wall voids, attics, basements, and crawl spaces. They also find refuge in cracks around windows and doors, behind baseboards, and sometimes even within furniture. These locations offer protection from cold, wind, and predators, allowing them to remain undisturbed until warmer weather returns.
When They Re-Emerge
Stink bugs remain in diapause until late winter or early spring when rising temperatures and increasing daylight signal the end of their dormant period. They then emerge from their hiding spots and become active again, often attempting to move outdoors to feed and reproduce.
Stink bugs may emerge on warmer winter days. If indoor heating causes temperatures to rise or they are disturbed, they may stir from their inactive state, appearing in living areas even in winter.
Keeping Them Out
Preventing stink bugs from entering homes is the most effective way to manage their presence. Sealing potential entry points is essential, as they can squeeze through very small openings. This includes inspecting and sealing cracks and crevices around windows, door frames, and foundations with caulk or weatherstripping.
Repairing damaged window and door screens is important, as is ensuring utility line entry points are properly sealed. Proper ventilation in attics and crawl spaces, along with screening vents, can further deter them. While a nuisance, stink bugs are generally not harmful to humans or pets and do not bite or spread diseases.