How to Get Rid of Boxelder Bugs
A black bug with red-orange lines on its back that feeds on the seeds of boxelder and maple trees. Large groups sun themselves on warm walls in fall before crawling inside. If you are seeing them indoors and on trees and shrubs, the steps below will help you clear them out and keep them from coming back.
Quick answer
- Seal gaps on the sunny side of the house
- Spray clusters on outside walls with soapy water
- Vacuum bugs that make it indoors
Boxelder bugs rarely bite and are harmless, but their droppings can stain curtains.
Confirm you have boxelder bugs
Before you treat anything, make sure you are really dealing with boxelder bugs. Adults measure 11–14 mm (up to about 0.55 in) and are usually black, red and orange. Look for these features:
- Black body with three red lines on the thorax
- Red edges along the wings
- Bright red nymphs clustered on tree trunks
They are most often confused with large milkweed bug and kissing bug. See the full boxelder bug profile for side-by-side details.
Why you have boxelder bugs
Boxelder Bugs come indoors looking for food, water, warmth or shelter. Gaps around doors, windows, pipes and utility lines give them easy ways in. Clutter, leaks and food left out let a small problem grow into an infestation. They are most active in fall and winter, so expect to see more of them then.
When you'll see boxelder bugs
Boxelder Bugs are most active in fall and winter. In fall, many bugs look for shelter, and some move toward or into buildings. In winter, activity continues mainly indoors in heated spaces.
Typical places to check: indoors, anywhere and trees or shrubs.
Step-by-step: getting rid of boxelder bugs
Step 1: Seal gaps on the sunny side of the house
Seal gaps on the sunny side of the house. Keep notes on where you still see activity so you can focus your effort.
Step 2: Spray clusters on outside walls with soapy water
Spray clusters on outside walls with soapy water. Repeat this for at least two to three weeks, since eggs and hidden insects keep appearing for a while.
Step 3: Vacuum bugs that make it indoors
Vacuum bugs that make it indoors. Combine this with the other steps rather than relying on it alone.
Natural and low-toxicity options
These methods work well alongside the steps above and keep chemical use to a minimum:
- Vacuum insects and egg cases, then empty the canister outdoors right away.
- Wipe surfaces with soapy water to remove scent trails and residue.
- Place sticky traps to find out where activity is highest.
- Run a dehumidifier where damp areas attract them.
If you do use a pesticide, choose one labeled for this pest and the place you're treating, and follow the label exactly. The label is the law.
When to call a professional
Call a licensed pest control company if you still see boxelder bugs after three to four weeks of steady effort, if they are spreading to several rooms, or if you share walls with neighbors who have the same problem.
How to keep boxelder bugs from coming back
- Seal cracks and gaps with caulk and install door sweeps.
- Store food in sealed containers and take out trash often.
- Fix leaky pipes and faucets and keep basements dry.
- Trim shrubs and branches so they don't touch the house.
- Keep firewood, mulch and debris away from the foundation.
Safety notes
Boxelder bugs rarely bite and are harmless, but their droppings can stain curtains.
Keep children and pets away from any traps, baits or treated areas.
About true bugs
The boxelder bug is one of the true bugs. True bugs have piercing, straw-like mouthparts used to suck plant sap or, in a few species, blood. They develop through gradual metamorphosis: nymphs look like small, wingless adults and molt several times as they grow. Many release strong odors from scent glands when threatened.
Because nymphs look like adults, you'll often see mixed sizes of the same bug together, which is a good sign that a population is breeding nearby.
Frequently asked questions
What is the fastest way to get rid of boxelder bugs?
Seal gaps on the sunny side of the house. Most people see a clear drop in activity within one to three weeks when they combine this with sealing entry points and removing whatever attracts them.
Are boxelder bugs dangerous?
Boxelder bugs rarely bite and are harmless, but their droppings can stain curtains.
When are boxelder bugs most active?
Boxelder Bugs are most active in fall and winter.
What do boxelder bugs look like?
Black body with three red lines on the thorax. Adults measure 11–14 mm (up to about 0.55 in).