How to Keep Boxelder Bugs Out of Your Home

Boxelder bugs are flying black bugs with red stripes that are annoying because they swarm in large numbers. These insects do not harm people or animals—even when they feed on plants, they don't cause serious damage. They may stain walls, furniture, and drapes with feces spots that are unpleasant, though not much of a health hazard.

Learn more about this pesky bug, what you can do to keep them out of your home, and better yet, prevent them, plus other information in this guide.

What Are Boxelder Bugs?

The boxelder bug (Boisea trivittatus) is a harmless but off-putting member of the stinkbug family. Although it's not related to cockroaches, it looks a lot like a roach, which many detest. When squished, it emits a foul odor.

Adults grow about 1/2-inch long and have black backs with orange or red stripes beginning behind the head. The wings lay flat over the body overlappingly, forming an X or upside-down V shape. The young bugs (nymphs) are only about 1/16-inch long and bright red upon hatching. They are avid flyers and can often travel for several miles at a time.

What Causes Boxelder Bugs?

Boxelder bugs enter your home for one reason—to find warmth during the cold months of winter. Boxelder bugs are attracted to boxelder trees and silver maple trees. If you have either of these trees around your home or neighborhood, you'll likely spot boxelder bugs at some point.

As soon as the cooler weather hits in the fall, boxelder bugs seek shelter for the winter and are often attracted to the warm, sunny sides of homes. From there, they slip into cracks and gaps in the siding or around doors and windows and can seek shelter inside the home during the winter.

5 DIY Ways to Keep Boxelder Bugs Out of Your Home

Vacuum the Bugs

Use a shop vacuum cleaner with a long hose attachment to gather live boxelder bugs from the exterior surfaces of your home. They most often congregate on the west and south sides of your house since these receive the most warmth from the sun. Vacuuming is also effective in winter for gathering bugs that have found their way into your home. Empty the vacuum cleaner bag into the outdoor trash immediately.

Clean Up After Landscaping

Remove piles of rocks, leaves, and other debris around your home. These areas provide the ideal hiding places for boxelder bugs and warm surfaces that attract them. Keep the area around the foundations free of leaves and weeds. Removing long grasses will discourage boxelder bugs.

Spray Exterior With Water

Dislodge bugs from the siding with a forceful spray of water. Boxelder bugs are easily drowned. Once they are washed off outside your home, they won't be able to get into the house through cracks and crevices.

A solution of two parts water and one part dish soap can be sprayed on the home's exterior to kill bugs in the fall. However, this has to be sprayed directly on the bugs—it does not have a residual effect on bugs landing on it. A soapy solution can also kill bugs that make it indoors. Sweep or vacuum the dead bugs.

Boiling water poured over groups of boxelder bugs will kill them; remember that this will also kill plants and grass.

Seals Cracks and Crevices

Caulk all cracks, crevices, gaps, and openings in your home's structure. The tiniest cracks allow boxelder bugs to enter your walls to escape the cold.

Although exclusion techniques won't permanently eliminate the boxelder bugs' entry, they can reduce the number of entry points and the number of bugs that get in. This is most effective when combined with other techniques.

Install and Repair Insect Screens and Weatherstripping

Repair any torn or broken door or window screens; boxelder bugs can fit through the tiniest tear in a window screen. Windows without screens should be equipped with new ones. Also, make sure the weatherstripping around windows and doors and below the garage door is in good condition.

How to Prevent Boxelder Bugs in the House

Eliminating breeding, feeding, and hiding spots around the exterior of your home will prevent boxelder bugs from reaching the interior. Seal cracks and crevices that allow them entry into your walls, and kill any bugs you see before they can get in.

Boxelder Bugs vs. Stink Bugs

The boxelder bug (Boisea trivittatus) is sometimes confused with the stink bug (various species in the Pentatomidae family of insects). Certain species of stinkbug bear a strong resemblance to B. trivittatus. Boxelder bugs release a strong, unpleasant scent when threatened, as homeowners may realize if they ever catch them by hand.

Boxelder bugs are identified by the red-orange veining and marking on the wings and abdomen, while only a few species of stinkbugs show such markings. Boxelder bugs are the species that routinely seek entry into the warmth of homes; stinkbugs don't exhibit this behavior.

When to Call a Professional

Although it sounds extreme, the most permanent control of boxelder bugs is the removal of any boxelder or silver maple trees near the home because these are the principal sources of food and breeding habitat. Boxelder, silver maples, and most ashes are not particularly valuable landscape trees, so removal by a tree professional may even improve the look of your yard.

Call a pest management professional to spray a residual insecticide on the home's exterior walls where the bugs are found. This will help prevent the bugs from landing for a while, but be aware that it will not remain effective once cold weather sets in. Toxic chemical sprays should be a last resort, and it's worth considering whether eliminating a harmless insect is worth the environmental risk.

Professionals typically apply residual pesticides since homeowners may not be allowed to purchase or handle them.

A professional can also use a power sprayer on the trees to kill the boxelder nymphs before they can grow into adults and move into your home. Be aware, though, that such pesticides will kill all insects, including beneficial pollinators. The use of toxic chemicals is questionable when controlling a harmless insect.