The "ladybugs" in your house this fall are most likely Asian lady beetles. In October and November, they look for a safe place to spend the winter. Sunny walls on your home look like a good spot, so they gather there and crawl in through small gaps. They don't bite, sting, eat food or breed inside.
Asian lady beetles, boxelder bugs and stink bugs all move into Missouri homes in the fall. If they keep getting in, our residential pest control service treats the outside of the home where these bugs gather and starts with a free inspection.
Why do ladybugs come in the house in the fall?
Asian lady beetles come inside in the fall to find a safe place to spend the winter. The University of Missouri Extension lady beetle guide says they gather in October and November on walls, windows, doors and decks that are light colored and face south or southwest.
Here is how it works:
- Days get shorter and cooler.
- The beetles fly to warm, sunny walls.
- They crawl in through torn screens, loose doors, cracks and vents.
- They hide in attics and inside walls all winter.
- On warm days, and again in March and April, they wake up and wander into your rooms.
That is why you can see them on a sunny day in December, even though they came in back in October.
Are Asian lady beetles harmful?
No. Asian lady beetles are a pain, but they are not a danger. MU Extension says they do not sting, bite or carry disease. A few people say they feel a small nibble. They do not eat wood, clothes or food, and they do not have babies inside your home in the winter.
There are three small downsides:
- Stains. When you crush or grab one, it can give off a yellow liquid that smells bad and can stain walls and fabric.
- Smell. Dead beetles in a vacuum bag can leave a smell that lasts for weeks.
- Allergies. A small number of people get seasonal allergies from them.
How can you tell an Asian lady beetle from a ladybug?
Look right behind the head. An Asian lady beetle has a white area with a black mark shaped like the letter M, says MU Extension. The beetle is about 1/4 inch long and can be tan, yellow, orange or red, with anywhere from 0 to 21 black spots.
What are the other fall bugs in Missouri homes?
Boxelder bugs and brown marmorated stink bugs move into homes in the fall too. All three want the same thing: a safe place to spend the winter.
| Bug | What it looks like | Where it gathers | Smell? |
|---|---|---|---|
| Asian lady beetle | About 1/4 inch, round, tan to red with spots, black M behind the head | Sunny south and southwest walls, then attics and walls | Yes, when crushed |
| Boxelder bug | About 1/2 inch, black with red lines on the back | Boxelder and silver maple trees, then the south and west sides of the house | No |
| Brown marmorated stink bug | About 5/8 inch, brown and marbled, white bands on the antennae | Outside walls on warm fall days | Yes, when bothered or crushed |
Sources: MU Extension lady beetle guide, MU Extension boxelder bug guide and MU Integrated Pest Management.
The MU boxelder bug guide says boxelder bugs can fly up to two miles to find a place to spend the winter. So you can get them even if you don't have a boxelder tree in your yard. You can read more about stink bugs in our stink bug pest library.
How do you keep lady beetles and stink bugs out of the house?
The best way to keep fall bugs out is to close the gaps they crawl through before they arrive. Once they are inside the walls, it is much harder. These steps come from MU Extension, including its 2024 tips on sealing your home:
- Caulk gaps. Seal cracks around doors, windows, siding and pipes on the outside of the house.
- Fix screens. Patch torn window screens and make sure they fit tight in the frame.
- Screen vents. Put insect screen over attic and exhaust vents.
- Add door sweeps. They block bugs and help keep heat in too.
- Clear the base of the house. Rake leaves and weeds back from the foundation, mostly on the south and west sides. Move piles of rocks, boards and junk away from the walls.
- Take out window AC units. The gaps around them are an easy way in.
What should you do with lady beetles already inside?
Vacuum them up. Don't squash them, since that can stain your walls. Then empty the bag or canister right away. MU Extension says you can let lady beetles go outside, away from the house, or drop them in a bucket of soapy water.
For stink bugs, MU Integrated Pest Management says a foil pan of soapy water under a light can trap them at night. They fly to the light and fall in.
Skip the bug bombs. MU Extension says indoor sprays don't work well on lady beetles, and MU IPM says not to use indoor foggers or sprays on stink bugs. Most of the bugs are hiding inside the walls anyway.
When should you call a pro about fall bugs?
Call when the bugs come back every fall, or when you see big groups on the outside walls. That usually means there are gaps you can't easily find or reach, like up high near the roof.
At Hometown Pest Solutions in St. Peters, we treat outside the home, where fall bugs gather before they get in. Our quarterly plans come with a 365-day pest-free guarantee, so if the bugs come back between visits, we come back too. If spiders are showing up too, see our post on why there are more spiders in the house in the fall.
Fall bug FAQ
Will lady beetles go away on their own? They will try to go back outside in March and April. Until then, they stay in your walls and attic and wander out on warm days.
Do lady beetles lay eggs in my house? No. MU Extension says they do not breed inside during the winter. The ones you see in spring are the same ones that came in last fall.
Why do they come back to the same house every year? They pick light colored walls that face south or southwest. If your house is like that, and the gaps are still open, they will find it again.
Are boxelder bugs harmful? No. MU Extension says boxelder bugs have no smell and do not hurt people, pets, wood or cloth. They are just a pest in large numbers.
Should I spray inside? No. Indoor sprays and foggers don't work well on these bugs. Seal gaps outside and vacuum up the ones inside.
Get help with fall bugs
If lady beetles, boxelder bugs or stink bugs are getting into your home in St. Peters, O'Fallon, Wentzville or nearby, we can help. Learn about our residential pest control service, request a free pest inspection, or call or text 636-297-1335. We are open 7 days a week.