Pest Control 101

How to Keep Unwanted Guests Out as the Weather Cools

August 24, 2025

As the crisp autumn air moves in, we all start getting ready for winter. But you're not the only one looking for a warm, cozy place to stay. As temperatures drop, all sorts of pests—from insects to rodents—will be looking for a way into your home. This simple guide will help you understand the most common culprits and what you can do to prevent them from becoming your unwanted houseguests.

If my hero photo gave you the heebie jeebies, you're not alone. I used AI to create that, and now I keep looking all over my office at home as I write this blog... it's best to follow these tips and make sure you're set for the coming cold weather!

The Usual Suspects: Common Montana Pests on the Move

In Montana, different pests seek shelter as the seasons change. Knowing who to look for is the first step in keeping them out.

Rodents

Mice and rats are the most common invaders. They can squeeze through shockingly small spaces—mice through a hole the size of a dime and rats through one the size of a quarter. They are seeking warmth, food, and a place to nest.

Take it from your girl here who just had to bleach down her entire garage with an N95 face mask after discovering tons of mouse poop all around her various shelves. I was not taking any risks sweeping that up, and was quickly frustrated knowing that we keep our garage quite clean year round. Mice and rats can move in an a whim and make themselves right at home.

Overwintering Insects

Some insects don't die in the winter but rather "overwinter" in a protected space. These include:

  • Boxelder Bugs: These bugs are common in the fall and often swarm on the sunny, south-facing walls of homes before finding a way inside. They are harmless, but quite annoying.
  • Ladybugs & Stink Bugs: These insects also seek shelter in large groups. While generally harmless, they can be a nuisance and may leave an odor or stain if disturbed – hence their name.
  • Spiders: As the weather cools, spiders naturally seek warmer shelter inside homes. This is also when some species, like the Hobo Spider, are most active, so it's a good time to be vigilant. Montana is home to various poisonous spiders, so it's best to mitigate as quickly as possible. *heebie jeebie shiver*
  • Other insects like cluster flies and certain beetles will also be on the hunt for a warm place to hibernate.
rat so gross

Finding the Entry Points: Where They Get In

The key to keeping pests out is to deny them entry. A thorough inspection of your home's exterior is the most effective preventative measure you can take.

  • Foundation & Walls: Inspect your foundation for any cracks or gaps, no matter how small. Look for any openings where the siding meets the foundation.
  • Doors & Windows: Check the weather stripping and door sweeps on all your exterior doors. Even a small gap can be a welcome mat for pests. Look for cracks in the caulk around window frames.
  • Vents & Chimneys: Pests love to use vents as highways into your home. Make sure your dryer, attic, and soffit vents have tight-fitting screens. Install a cap or screen on your chimney.
  • Pipes & Utility Lines: Check the areas where pipes, electrical wires, and utility lines enter your home. These are often overlooked points of entry.

Your Proactive Maintenance Checklist

You can take several simple, DIY steps to make your home an impenetrable fortress against pests:

  • Seal Everything: Use silicone caulk or expanding foam to seal cracks and holes in your foundation and walls. For larger holes that pests can chew through, use steel wool or copper mesh, as they can't gnaw through it. Trust me, if mice want in, they'll try their hardest!
  • Tidy the Yard: Clean up fallen leaves, branches, and other debris near your home's foundation. Pests love to hide in this clutter and you'll feel so much better to tidy this up before the snow starts sticking.
  • Store Firewood Away: Keep firewood piles at least 20 feet away from your home. Firewood is a prime hiding spot for many insects and rodents. WEAR GLOVES when you handle firewood left out in the yard. I've had plenty of instances where I battled a spider while moving wood. 
  • Trim Branches: Cut back any tree branches or shrubs that are touching your home's siding or roof. They act as "bridges" for squirrels, mice, and insects to gain easy access.
  • Check Screens & Gutters: Make sure window screens are free of tears and that your gutters are clean and draining properly. Standing water can attract pests (and also cause water damage).
  • Get a Barn Cat: I can never stress enough how beneficial a good outside cat can be. They're practically self-sufficient and are natural hunters that can help with the smaller to medium sized pests. Bonus: most animal shelters allow for free adoption to "working cats" that are feral, neutered/spayed, and in need of a good home where they can be put to work on pest control.
firewood

When to Call a Professional

While a good DIY approach is a great first step, some infestations require professional help.

  • If you find evidence of an existing infestation (e.g., droppings, gnaw marks, or a large number of pests indoors).
  • If the problem persists despite your best efforts.
  • If you suspect a dangerous pest, like a Black Widow spider (one last heebie jeebie shiver), or larger animals like bats or raccoons that may carry rabies.

A little bit of proactive maintenance now can save you a lot of headaches later. By following this simple checklist, you'll ensure your home is cozy, safe, and pest-free all winter long.

Thinking about buying or selling a home and need to know what to look for? Contact me for an expert consultation on preparing your home for a pest-free sale or a smooth purchase!