Stink Bugs
Halyomorpha halys (brown marmorated stink bug)
NuisanceWhat it is
Shield-shaped true bugs that release a strong odor when disturbed. Some species damage crops, while others enter buildings in fall to overwinter and become nuisance invaders.
How to recognize it
- Mottled brown and shield-shaped, about the size of a thumbnail
- Pale bands on the antennae and along the edges of the body
- Clusters on sunny sides of houses, around windows and doors in fall
- Released smell when disturbed or crushed
Where you will find it
On sunny walls and window screens in fall, then in attics, wall voids, and cracks. Outdoors they feed on garden crops and fruit.
Established in most of the US.
Why it matters
They do not damage a house, but large groups indoors are a nuisance.
Look-alikes
- Native stink bugs: Often greener or with different markings, and less likely to gather in large numbers on homes.
- Western conifer seed bug: Narrower, with flattened leaf-like hind legs. It also comes indoors in fall and is harmless.
What to do
- Vacuum them up and empty the vacuum right away, or sweep them into a bucket of soapy water. Don't squash them.
- Skip indoor sprays and bug bombs, which don't solve the problem.
- Contact a professional before fall. Closing entry points and treating the outside at the right time works best.
When to call a professional
- They keep coming back every fall.
- You want exterior treatment timed for early fall.
Questions
Do stink bugs bite?
No. They don't bite or sting, and they don't damage your home or food.
Why do they come out in winter?
Some hide in walls and attics and wake up on warm days, which is normal.
Can they harm my garden?
Yes. They feed on many fruits, vegetables, and ornamental plants.
Related reading
Related pests
Occasional Invaders
A broad category for pests that enter buildings incidentally but usually do not reproduce indoors. Examples can include boxelder bugs, lady beetles, millipedes, ground beetles, and other seasonal invaders.
Read more →Boxelder Bugs
Black-and-red true bugs associated with boxelder and some maple trees. They often gather on sunny exterior walls and enter buildings in large numbers to overwinter.
Read more →Clover Mites
Tiny reddish mites that feed on grasses and ornamental plants. They often invade buildings in large numbers around windows and foundations but do not bite people or damage household items.
Read more →Cluster Flies
Slow-moving flies that enter buildings in late summer or fall to overwinter in attics and wall voids. Their larvae develop as parasites of earthworms outdoors; indoor adults do not breed in garbage or drains.
Read more →This page is general information, not a diagnosis. Pests vary by region and situation, and an on-site inspection is the reliable way to know what you have.