Why Fall Invites Unwanted Guests Indoors
The common fall pests that move indoors in October are spiders, mice and rats, and moisture-loving centipedes and millipedes. As temperatures drop, they look for shelter, warmth, moisture and food, and they get in through cracks in the foundation, gaps around doors and windows, and unsealed openings where pipes and utility lines enter the house. Sealing those gaps, fixing damp areas and clearing debris away from the foundation make a home much less inviting to them.
Saela Pest Control is a residential and commercial pest control company that helps homeowners keep spiders, rodents and other fall invaders out. Fall pests head for buildings as the weather cools, and you may first notice them as a spider in a basement corner, a centipede in the bathroom or droppings in the pantry. Below, Saela explains which fall pests are common indoors, which ones carry real risk and what to seal or fix now; for what happens once it turns colder, see where pests go in the winter.
Leaf piles, mulch, firewood and other debris against the foundation act as staging areas, giving pests cover right next to the house before they find a way in. Millipedes, for example, live in and feed on rotting leaves, rotting wood and other moist, decaying plant matter. Removing that material from around the foundation takes away much of the cover before pests reach the walls.
Common Creepy Crawlers Making Their Move
Spiders and rodents are two of the most familiar fall invaders. Many spiders, like many insects, look for a protected place to spend the winter, and indoors they settle in quiet corners of basements, attics and closets where insect prey is easy to catch. Mice and rats look for food and nesting spots in kitchens, pantries and storage areas, and they need very little room: the CDC notes that mice can fit through a hole the width of a pencil, about a quarter inch across. Saela’s guide to how mice and rats get inside walls explains what happens once they are in.
Centipedes and millipedes need damp conditions, so indoors they turn up in basements, bathrooms, closets and crawl spaces. According to UC IPM, centipedes don’t damage household items, and millipedes that wander indoors usually die quickly because the air is too dry and there is little to eat. Seeing them often is a sign of excess moisture, such as a plumbing leak, poor drainage or a damp crawl space, or of easy gaps along the foundation. Fixing the moisture and sealing those gaps deals with the cause rather than the bugs you happen to see.
Pro tip: A few times this fall, check your basement, attic and crawl space with a flashlight for droppings, webs, gnaw marks and damp spots. Small signs are much easier to deal with before pests settle in.
The Hidden Risks of Indoor Pest Infestations
Most fall invaders are a nuisance, but rodents can cause real harm to a home and to your health. Purdue Extension notes that house mice gnaw on wiring and building materials, which can create fire hazards, and that they contaminate food with their urine, droppings and hair. Mice can also pass diseases to people, including salmonellosis, a form of food poisoning.
Most spiders and centipedes are more unsettling than harmful, though a few spiders are a medical concern, such as black widows and, in the southeastern United States, brown recluses. Spiders also feed on pest insects, and some large centipedes can give a painful bite when provoked, so avoid handling either with bare hands. Identifying the species comes first, and at Saela, Dennis Weiss, BCE, Saela’s board-certified entomologist, develops the pest-control protocols, trains the technicians and audits service quality. Often the bigger concern is what these pests say about gaps and moisture, so acting early keeps a small problem from becoming a larger one.
Proactive Steps to Prevent Fall Pest Invasion
Start outside by sealing the gaps pests use. Check for cracks in the foundation and gaps around windows, doors, vents and where pipes and wires enter; Montana State University Extension’s guide to fall home invaders also recommends repairing screens, installing door sweeps and keeping wood piles and debris away from the house. For rodents, the CDC recommends steel wool held in place with caulk or spray foam for small holes, and hardware cloth, metal sheeting or cement for larger ones. If you’d rather have it done for you, Saela’s rodent exclusion service includes inspecting for access points, repairing openings and placing traps for any rodents still inside.
Inside, focus on moisture, food and clutter: repair leaks, use a dehumidifier in damp basements, store pantry and pet food in sealed containers, take garbage out promptly and clear clutter from basements, garages and storage areas where spiders and mice hide. Saela’s integrated pest management approach works the same way, pairing sealed entry points with less food, water and shelter for pests. No single step keeps every pest out, but together these habits make your home much less inviting.
Extra tip: Check your outdoor lighting. Mississippi State University Extension notes that insects gathering around exterior lights also attract spiders, and that yellow bug lights, yellow LEDs and high-pressure sodium lights are less attractive to insects. Fewer lights, timers or motion sensors, and fixtures shielded to point down also help.
When to Call the Professionals for Help
Call for help when the signs point to pests living inside rather than passing through: droppings, gnaw marks, scratching in walls or ceilings, or spiders and centipedes showing up week after week. Every Saela plan includes a 50+ point property inspection that covers entry points, attics and basements. Because fall invaders come back each year, a recurring plan can catch activity before it builds: Saela’s Protection Program includes interior and exterior treatments with every-other-month or quarterly visits, depending on the plan.
In a February 2024 Google review, Kimberly Cummings wrote, “I’m pleased with the job John did at my quarterly service.” If spiders, rodents, centipedes or millipedes are already settling in, book a call to schedule an inspection.
Who wrote this article?
Devin Hutchings (Marketing Director at Saela Pest Control) wrote this article.
Devin leads Saela’s marketing and growth strategy. He brings more than 15 years of marketing experience across Uber, C.R. England, Lugg, and Neighbor. His background spans customer acquisition, retention, and developing marketing channels for service businesses and consumer marketplaces.
