Overwintering pests are those that take shelter in a protected area to avoid the harsh elements of winter. These protected areas are oftentimes our homes and other buildings. Pests will often make their way unnoticed indoors in the fall in search of this protected shelter and to also be closer to a ready food supply during the scarce winter months. Wall voids and attic spaces are common areas where overwintering pests hide out until they are ready to emerge. They usually won’t come back out until spring but unseasonably warm weather spells during the winter months can bring them out early. This is when you will see them make an appearance in your home and they can reveal much larger problems than you anticipated.

Here are four of the most common overwintering pests, along with some tips on how to prevent them from invading your home.

Brown Marmorated Stink Bug

Brown Marmorated Stink Bug
The brown marmorated stink bug is an invasive species from Asia that has recently spread to much of the United States. They spend most of their life cycle outdoors but will often overwinter in large numbers in homes and buildings. These pests are 1/2″ in length, shaped like a shield, and are brown in color with a marbled (marmorated) pattern. In the summertime they feed on fruit trees, ornamental plants, and vegetables and are capable of destroying entire crops. Once they make their way indoors, they will emerge again when the weather warms up. They will emit noxious odors when crushed or stressed. The best way to eliminate stinkbugs once they are in your home is to vacuum them up and dispose of the bag immediately afterwards.

Asian Lady Beetles

Asian Lady Beetle
While Asian lady beetles look a lot like native ladybugs, they are indeed different. Most Asian lady beetles pose no threat to humans but they can cause allergic reactions and aggravate asthma. They can also give off a foul-smelling, yellow fluid that has been known to leave stains. While they don’t cause structural damage to homes, they can be quite a nuisance, especially in large numbers.

Boxelder Bugs

Boxelder Bug
Boxelder bugs are a minor garden pest in the summer time that can become a major nuisance in the winter months. These pests are 1/2″ in length and black with red markings. They feed on the seeds of boxelder and other maple trees and will often congregate on warm spots on buildings before migrating indoors. They can easily slip through cracks and crevices of homes and other buildings where they will stay until the weather warms up again. They don’t stink or transmit diseases but they will occasionally bite when handled. They don’t cause structural damage to homes but their feces will discolor fabric.


While rodents don’t technically overwinter because they are active year-round, they will migrate indoors in the winter months to nest and be closer to a readily available food supply. These pests can cause significant damage to your home and your health. Their constant gnawing can cause serious structural damage and the potential for electrical fires. They can also contaminate food by defecating on surfaces where food is prepared. Their feces can also aggravate asthma and allergies. They are also known to carry significant diseases that can be transmitted to humans.


Once overwintering pests are inside your home, there isn’t much you can do to eliminate them until the weather warms and they start to emerge. The best way to control overwintering pests is to prevent them from getting into your home in the first place. Here are some tips to prevent overwintering pests from invading:

  1. Carefully inspect the exterior of your home to identify any potential entry points these pests can use.
  2. Seal cracks and fill gaps around door and window frames, the bottom of siding, roof lines, fascia boards, soffits, attic vents, and chimney flashing.
  3. Seal cracks with silicone or silicone-latex caulk and fill holes around utilities with steel wool.
  4. Repair torn screens on doors and windows and install door sweeps on exterior entrances.
  5. Create a barrier zone around your home by sweeping pine straw, mulch, and bark at least 6 inches away from foundations.
  6. Clean gutters to remove debris.
  7. Keep your home, especially kitchens, clean and crumb free.
  8. Vacuum often.

If you have an overwintering pest problem or want to get ahead of the invasion, contact a professional pest control company who can help identify any pest issues you may have, thoroughly evaluate your home for potential entry points, and provide you with a comprehensive pest control treatment plan.