Boxelder Bugs, Why You’re Seeing Them and How to Get Rid of Them
- Nov 24, 2025
- 3 min read
Ever notice clusters of black and red bugs crawling on your walls, windows, or the sunny side of your house? Those are boxelder bugs, and fall is when they make themselves known in Rialto, Fontana, and across Southern California. They’re harmless but annoying, and if they make it inside, they’ll drive you crazy fast.
Let’s break down why you’re seeing them, where they live, what they eat, and the best way to keep them out of your home.
What Are Boxelder Bugs?
Boxelder bugs are small, flat insects about half an inch long. They’re black with reddish-orange markings on their backs and wings. They don’t bite, sting, or carry disease, but when they show up in large numbers, they’re a nuisance.
Their name comes from their favorite tree — the boxelder tree, a type of maple that’s common throughout Southern California neighborhoods.
Why You’re Seeing Them Now
You’ll notice boxelder bugs the most during fall. As the weather cools, they start looking for warm, dry places to spend the winter. Your house, attic, garage, or wall voids are perfect for them.
They gather in large groups on sunlit walls, windows, and doors during the day to stay warm. Once they find a way inside, they’ll hide in cracks, behind siding, and around window frames until spring.
If you’re seeing a bunch of them outside, there’s a good chance they’re getting ready to move in.
Where Boxelder Bugs Live and What They Eat
Outside, boxelder bugs live on boxelder trees, maple trees, and ash trees. They feed on seeds, sap, and newly developing leaves. They don’t damage trees badly, but when they gather in large numbers, they leave behind stains from droppings and crushed bodies.
Inside, they don’t feed or reproduce. They’re just looking for shelter until the weather warms up again. But once they find a way in, you’ll start seeing them around windows, vents, light fixtures, and baseboards.
Why You Don’t Want Them Inside
Even though boxelder bugs don’t bite or eat your food, they’re still a problem.
They stain walls, curtains, and furniture with their droppings.
They release a bad smell when crushed.
Large infestations attract spiders and other insects that feed on them.
Once they find shelter, they come back year after year.
What starts as a few bugs in the fall can turn into hundreds by next season if left untreated.
How to Get Rid of Boxelder Bugs
There are a few steps you can take to control them:
Seal cracks and gaps around windows, doors, and siding.
Vacuum up bugs instead of crushing them to avoid stains and odor.
Spray around entry points with a labeled insecticide.
Remove nearby boxelder or maple trees if they’re attracting large populations.
Call a professional pest control company to apply a barrier treatment that stops them before they get inside.
Professional Boxelder Bug Control in Rialto and Fontana
At TruPest Solutions, we know boxelder bugs are more than a seasonal annoyance — they’re a sign pests are finding easy access to your home. Our treatment plans target the bugs where they gather, treat entry points, and prevent future infestations before they move indoors.
We use safe, effective methods that protect your home while keeping your walls, siding, and windows free from stains and clusters of bugs.
If you’re tired of seeing black and red bugs on your house or finding them crawling inside, we’re ready to help.
Call 951-334-5288 or visit TruPestSolutions.com to schedule your boxelder bug control service in Rialto or Fontana today.
