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If you’ve spotted little black-and-red insects hanging out on your siding or sneaking across your windowsill, you’ve officially entered boxelder bug season. Similar to stink bugs, these bugs tend to visit during the fall. While these bugs aren’t dangerous, their mere presence and persistence make them an annoyance. And once they’ve found a cozy spot inside, they’re not leaving until spring.
This year, boxelder bugs seem especially bad, thanks to a warm, dry summer that made for a bumper breeding season. As temperatures cool, they’re searching for somewhere to overwinter—and your home might be the perfect place.
What exactly are boxelder bugs?
Boxelder bugs are half-inch-long insects that are easy to spot: matte black bodies with red or orange outlines, and wings that form a bright X pattern across their backs. The younger nymphs are even flashier with vivid red and wingless until they mature.
They love maple, ash, and (of course) boxelder trees, where they feed and lay their eggs during warmer months. When fall arrives, they migrate toward warm, sun-soaked surfaces. Think south-facing walls, roofs, and windows, right before slipping inside through the tiniest cracks.
While they don’t bite, sting, or cause any major damage, they release a strong odor when crushed and can stain walls or curtains.
Like the stink bug, boxelder bugs are a classic “shoulder-season pest.” When it’s too cool to stay outside but too early for frost, they start scouting for shelter. And once they’re in, they’ll hunker down behind walls, under baseboards, or near heating ducts until spring sunshine lures them back out.
The best ways to keep them out
Seal the cracks before they do
Boxelder bugs are great at finding tiny gaps. Walk the perimeter of your house and seal any cracks or openings around windows, doors, vents, or siding with caulk or weatherstripping. Torn window screens? Patch them up.
Soap spray for the win
Skip harsh pesticides and make a simple soapy spray: one tablespoon of dish soap in a cup of water. Spritz it directly on clusters outdoors; it suffocates the bugs and deters new ones from gathering.
Vacuum, don’t squash.
Crushing them will release a stinky odor and leave behind bright orange stains. Instead, vacuum them up and empty the canister or bag outside immediately (otherwise, they might crawl back out—yes, really).
Target their favorite hangouts.
They tend to gravitate towards warm, sun-facing walls and windows. Keep these areas clean and regularly spray them down with soapy water to break up clusters before they multiply.
Tidy up your trees
If you have seed-bearing boxelder, maple, or ash trees nearby, removing fallen seeds or trimming the trees helps reduce their population.
Try diatomaceous earth
For a chemical-free barrier, sprinkle food-grade diatomaceous earth around the bases of trees and along your home’s foundation. It’s harmless to pets and people but deadly to boxelder bugs—it dehydrates them on contact.
Mind your vents and outlets.
Boxelders love the heat, so check electrical outlets, light fixtures, and air vents—especially if you feel drafts. Tighten loose covers and add foam gaskets behind outlet plates to block their entry points.
