FM Articles

Exclusion: Your Best Option for a Pest-Free Winter


As 2020 continues to sizzle, a retreat to a cool weather resort sounds like a great idea. But before you burn a vacation day to leave the heat behind, be sure to prepare for the fall invasion. We’re not talking about another virus or any other catastrophe; we’re talking about the fall pest invasion. Across the country, pest management professionals are aggressively preparing to exclude, or block out, every sort of pest that wants to overwinter in facilities like yours. That is why right now, when it is still warm, pest management technicians are performing detailed inspections to prepare facilities for the inevitable.

Avoid the mistake many people make – acting too late to prevent pests. Many believe that pests start searching for warmer spaces after people begin wearing long-sleeve shirts and sweaters. This common misperception causes many to suffer through a winter full of pests. It’s important to know that a pest that survives in your climate is highly attuned to the weather that is coming and begins moving indoors as soon as it senses the change, based on its biological indicators. In the north, even though there may not be snow until the New Year, multi-colored Asian lady beetles, boxelder bugs, and brown marmorated stink bugs will begin to invade facilities as early as September. Rodent activity can also pick up as early as August! While seasonal pest pressures affect southern states too, the experience is different as pests may invade later in the year. Regardless of where you live, the key is to not wait until you see pests inside, but to start planning now.

Step 1:  Understand the Opponent
Whether you are coaching a high school football team, heading out for the big hunt, or controlling pests, the best place to start is by understanding the opposition. In the pest management industry, that means understanding the pests and environment surrounding the facility being protected. In order to do that, ask:

  • What pests do we face here?
  • Do they fly, walk, or slither?
  • How big are they?
  • Do they like low levels (soil) or do they prefer higher elevations (roof lines/overhangs)?

When you take the time to find out which pests are present, you can focus your efforts and do a better job of excluding them. For instance, if you find a rat in a Wisconsin facility, you would start sealing any gaps near the ground. However, implementing the same procedures in Texas may not help the situation at all. The difference in effectiveness is found in the habits of regional rodents (Norway rats versus roof rats). Norway rats dig their homes in the safety of the soil. Roof rats are the opposite and find comfort in nesting in high places.

The same could be said for flying insects versus crawling insects, insects versus rodents, or snakes versus, well, anything else. Knowing what you are up against will help optimize your time and efficiency.

Step 2:  Inspect Your Facility
For this step, you do not need high tech equipment like a thermal-imaging camera (although one would be awesome). A flashlight, an inspection mirror, a pen, a flat-head screwdriver, and a new perspective are all you need for facility inspection.

Begin your inspection with the attitude that any crack, gap or break in the facility – from the chimney cap to the utility connections below ground – needs to be sealed. Start inside by checking door seals and basement sill plates for any light entering from outside. Also, look for signs of air flow from outside. This could be done by feeling for air movement or subtly observing air movement by looking at cobwebs. Don’t forget to look in the attic space, too.


On the outside of your facility, check any areas where two materials join. Some examples include:

  • Siding: overlap, corners, windows, foundation, joints
  • Masonry: tuck pointing, gaps, voids at connections to other materials
  • Windows: broken panes, loose caulk, poor installation, torn screens
  • Soffit: gaps, vents
  • Trim: loose facia, holes chewed in
  • Roof: flashing, chimney masonry, chimney cap, vents
  • Utilities: pipes or lines entering or leaving

The number of areas to inspect seems daunting, but if you make a plan and commit to repairing any opening in your building to exclude pests, you will reap the rewards for months or even years to come!

Step 3:  Make Repairs
Once you have determined what repairs are needed to exclude pests, you need to select the right materials to do the job. Hydraulic caulk, construction adhesive, and silicone caulk may all come in the same tube, but they are not the same product. Before you determine which product to use, you need to consider the materials you plan to apply them to. This is also true of the type of pest you are looking to control. Caulk may keep out insects, but hardware cloth, mortar or sheet metal may be necessary for vertebrae pest like rodents. Other materials to use include steel wool, weather sweeps, copper mesh, sheet metal, concrete patches, hardware cloth, escutcheon plates, and expanding foam.

Aside from materials, it is also important that you find the right person for the job. If you choose to delegate someone to perform this work, keep in mind that the employee or tradesperson you choose will have different skill levels and limitations. Choosing the right person for the job will be the difference between a job half done and a job well done.

Step 4: Simply Ask for Help When Needed
This work may overwhelm you or not be a good use of your time, and that’s okay. There are many professionals that you can ask to assist you. From pest-proofing inspections, to repair work and treatment options, many pest management companies offer all these services.

So, while you suffer through another August afternoon, pull up a lawn chair, grab a glass of sweet tea, and something to take notes with, and begin planning your exclusion strategy for this winter. Or skip the dirty work and give a pest management professional a call. Either way, you can do this, and time is still on your side–for now.

Alex Blahnik, ACE, is a field training manager at Wil-Kil Pest Control, a Copsean Pest Solutions Partner and regional pest management company providing quality pest management for residential and commercial properties throughout the Upper Midwest. Since 2000, Blahnik has been in the structural pest management field and is an Associate Certified Entomologist (ACE).