What Are Occasional Invaders and Why Do They Show Up in Fall?
There is a whole category of pests that do not really want to live in your house. They are just trying to get out of the weather, and your home happens to be in the way. Pest folks call them occasional invaders, and fall is their season.
What counts as an occasional invader
These are outdoor bugs that wander inside in small numbers rather than infesting the way roaches or ants do. Common ones around Alabama include:
- Stink bugs and boxelder bugs gathering on warm, sunny walls
- Crickets showing up in basements, garages, and around doors
- Millipedes and centipedes coming in from damp mulch and leaf litter
- Ladybugs, or the look-alike Asian lady beetles, clustering on the sunny side of the house
They do not breed indoors, do not damage your home, and are more of a nuisance than a threat. But when a dozen show up on a window, it does not feel minor.
Why fall specifically
As nights cool, these insects instinctively look for a protected spot to ride out the coming cold. They cluster on sunny exterior walls in the afternoon, then slip inside through gaps around windows, doors, siding, and the foundation. A warm fall afternoon after a cool night is prime time to see them massing on the south and west sides of a house.
How to keep them out
- Seal gaps around windows, doors, siding, and utility penetrations, which is the single biggest thing you can do
- Add or repair door sweeps and window screens
- Rake leaf litter and pull mulch back from the foundation to reduce the damp cover they gather in
- Vacuum up the ones that get in rather than crushing them, especially stink bugs and lady beetles that can leave a smell or stain
The Alabama angle
Our up-and-down fall, warm afternoons and cool nights, is exactly the pattern that triggers these bugs to seek shelter, so we tend to see more of them than states with a quick, sharp turn into winter. Sealing the exterior before the first cool nights is the move. This overlaps with the broader fall pattern we cover in what pests are most active in Alabama each season.
Fall bugs collecting on your windows and doors?
Our residential pest control seals and treats the exterior so they stop finding their way in. Call or text (205) 855-7975.
Get a Free EstimateWhat are occasional invaders?
Pests that live outdoors most of the year and only come inside now and then, usually when the weather changes. They do not breed indoors or damage the home, but they are a nuisance in numbers.
Why do stink bugs and ladybugs appear in fall?
Cooler nights push them to look for winter shelter. They cluster on warm, sunny walls in the afternoon and slip inside through gaps around windows, doors, and siding.
What is the best way to keep them out?
Seal the exterior. Closing gaps around windows, doors, siding, and utility lines, plus good door sweeps and screens, keeps the large majority of them outside.
