Why Bugs Try to Move Into Lincoln Homes in October, and How to Keep Them Out

If you have noticed a cluster of black and red bugs sunning themselves on the south side of your house lately, or found a ladybug crawling across the kitchen window on a warm afternoon, you are not imagining it. October is when a lot of Lincoln homeowners suddenly realize they have company.

It can be unsettling. Nobody likes the idea of bugs moving into the walls, and finding them in a child's bedroom or on the living room ceiling feels like the house is being invaded. The good news is that most of these fall visitors are more nuisance than threat, and once you understand why they are coming in, keeping them out gets much more manageable.

Why Fall Brings Bugs Indoors

Many insects in Nebraska survive winter as adults. To do that, they need a sheltered spot that stays above freezing and out of the wind. In nature, that might be under tree bark, in leaf litter, or inside rock crevices. But a house offers something better: walls warmed by the furnace, attic spaces, and countless small gaps that lead inside.

As the days shorten and temperatures drop, these insects start looking for overwintering sites. They are drawn to warmth, so on sunny fall afternoons they gather on the south and west sides of buildings where the siding soaks up heat. From there, they crawl into whatever openings they can find. Most of them are not trying to get into your living space at all. They are trying to get into your walls. Some just keep wandering until they end up in the rooms where we live.

The Fall Invaders We See Most Around Lincoln

Boxelder bugs are probably the most familiar. They are about half an inch long, black with red or orange markings, and they often show up in large numbers on homes near boxelder, maple, or ash trees. They do not bite people or damage the structure, but they can stain curtains and walls if crushed.

Multicolored Asian lady beetles look like the ladybugs most of us grew up with, but they vary from pale orange to deep red, with or without spots. They are helpful in the garden because they eat aphids, but they gather on homes by the hundreds in fall. When disturbed, they can release a yellowish fluid with an unpleasant odor that can stain, and some people notice they will occasionally pinch.

Stink bugs, including the brown marmorated stink bug, have become more common in parts of eastern Nebraska. They are shield-shaped, mottled brown, and known for the strong smell they release when handled or crushed.

Crickets move toward homes as fields and gardens die back in fall. They are more annoying than harmful, mostly because of the chirping that can echo through a basement at night.

Spiders also become more noticeable this time of year, partly because many species are reaching their adult size and partly because males wander in search of mates. We cover spiders in more detail in a separate article, because they are one of the most common reasons homeowners call us in October.

Do They Cause Real Damage?

For the most part, the honest answer is no. Boxelder bugs, lady beetles, and stink bugs do not breed inside your home over the winter, do not eat wood or fabric, and do not carry diseases to people. They are a nuisance rather than a structural threat.

That said, nuisance is a real problem when it is happening in your house. Stains from crushed insects, odors, bugs falling from ceiling light fixtures, and dead insects collecting on windowsills in spring are all things most families would rather avoid. And large numbers in a wall void can attract other pests that feed on dead insects.

How They Get In

Imagine walking around your home with the eyes of a boxelder bug. Every gap matters. The most common entry points we find around Lincoln homes are gaps around window and door frames, worn or missing door sweeps, torn window screens, openings where cable, gas, or electrical lines enter the house, unscreened attic and soffit vents, gaps under siding and along the foundation, and spaces around air conditioning lines and dryer vents.

Most of these openings are small, often an eighth of an inch or less, which is all many insects need. Older homes tend to have more of them, but even newer construction develops gaps as the house settles and caulk ages.

Step One: Close the Doors They Use

Sealing entry points is the foundation of keeping fall invaders outside. Fresh caulk around window and door trim, new door sweeps, repaired screens, and sealant around utility penetrations all make a difference. Screening attic vents is also helpful, as long as the vents are not blocked.

Exclusion is not glamorous work, and it is rarely perfect. Even a carefully sealed home will have small gaps somewhere. But every opening you close reduces the number of insects that end up inside.

Step Two: An Exterior Perimeter Treatment

The second step is a perimeter pest control treatment applied to the outside of the home. This typically targets the foundation, the areas around doors and windows, eaves, and other places where insects gather and travel. The goal is to stop them on the outside, before they work their way into the walls.

Timing matters here. A perimeter treatment is most effective when it goes down before insects settle in for the winter. Once they are already inside wall voids, an exterior application cannot reach them. That is why we encourage homeowners to schedule fall treatments in September or early October, when insects are first gathering on the warm sides of the house.

What to Do If They Are Already Inside

If you are already finding fall invaders inside, the simplest and most effective tool is a vacuum. Vacuuming bugs off windows and walls removes them without crushing them, which avoids stains and odors. Empty the vacuum bag or canister outside afterward.

We generally do not recommend spraying insecticides indoors for these pests. It rarely reaches the insects hidden in wall voids, and the ones you see are usually just the stragglers that wandered out. The better approach is to vacuum what you see, then focus on sealing and outdoor treatment to reduce the numbers next year.

On warm winter days and again in early spring, some of the insects that overwintered in the walls may wake up and wander into the house. That is normal, and it usually tapers off once they head back outside in spring.

What a Protected Home Looks Like

Imagine a sunny afternoon in mid October. On the neighbor's house, boxelder bugs are clustered by the dozens around the back door. On yours, a few are crawling on the siding, but they are not finding a way in. Inside, your windowsills are clean, the kids are not finding lady beetles in their rooms, and nobody is chasing stink bugs off the curtains.

That is a realistic goal. Not zero bugs in the yard, but bugs that stay outside where they belong.

What to Do Next

Here is what we recommend this month. Walk around your home and look closely at windows, doors, siding, and utility lines for gaps. Seal what you can with caulk and weatherstripping, repair screens, and replace worn door sweeps. Vacuum any insects that have already made it inside rather than crushing them.

If you would rather have someone else handle the outside of the house, we are here for that. Yard Boss offers perimeter pest control in Lincoln, Crete, and the surrounding area. Call 402-588-4222 or visit yardbosslawns.com to request a free quote.

Here is what to expect. A licensed Yard Boss technician will walk the outside of your home, point out the areas where insects are gathering and getting in, and explain what we will treat and why before we start. We will let you know when we are coming and what to expect afterward, so you know exactly what was done around your home.

Related: Pest control · Fall pest prevention for Nebraska homes · What perimeter pest control costs in Lincoln · Get a quote