The Sneaky Way That Pests Are Getting Into Your Home (& How To Prevent It)

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Most homes rely on the standard defenses, including locked doors, sealed windows, and perhaps a screen or two to keep bugs out. It's easy to assume that with these in place, the house is airtight against intruders, both the two-legged and six-legged kind. But it's usually not an open window or cracked screen that's the real problem. It's the small, unnoticed cutouts around utility lines. The holes where pipes, cables, or wires slip through your walls may look harmless, but for pests, they're the equivalent of an unlocked back door. This is the subtle way they're getting inside, and sealing those openings is one necessary way to remove pests from your home.

And make no mistake, pests aren't an uncommon issue. According to the National Pest Management Association (NPMA), rodents alone infest about 21 million U.S. homes every winter, gnawing their way into pantries and wiring. Millions of Americans also report spotting a cockroach scuttling across their floors, and that's not even counting the flies, ants, termites, and bedbugs that add to the daily battle. Beyond being unsightly, these pests carry health risks. They spread bacteria and damage the very structures we live in. Blocking their access points is one of the most important steps you can take to protect your home.

When builders cut holes for plumbing pipes, electrical wiring, or gas lines, they often make those openings just a little larger than necessary. The goal isn't to invite pests in, of course. It's practicality. They want the installation to fit easily, and precision isn't the priority when the main focus is getting the utilities to be functional. But this plumbing mistake can cause more damage than you think. If it's not closed properly, the extra space around the line becomes a perfect hideaway and highway. Rodents, spiders, roaches, ants, and other uninvited pests will see those gaps as secret tunnels that lead straight into your home.

Pests are masters at finding paths that keep them invisible. A mouse only needs a hole the size of a dime to get inside, and cockroaches flatten their bodies to squeeze into cracks that look impossible to the human eye. That's why these utility cutouts are so appealing. They're small enough to go unnoticed by you, yet just right for something that wants to stay hidden while coming indoors. Some of the most common places to check include behind your refrigerator or stove, under sinks where pipes enter, in the laundry room near washer hookups, and along basement or crawl space walls. In short, any spot where a line runs through a wall deserves a closer look, because chances are, that's where pests are already testing your defenses.

Once you've spotted those gaps, the upside is they're not hard to deal with. All you need is the right materials. For irregularly shaped openings, expanding foam is often the easiest fix to keep pests far away. It swells to fill the space, hardens in place, and instantly cuts off the entry point. But foam alone isn't always enough. Rodents, in particular, are relentless chewers. That's where steel wool can help. Stuffing it into the gap makes the passage nearly impossible to gnaw through.

To finish the job, a layer of weatherproof sealant helps lock everything in place and keeps the repair long-lasting. In areas where fire safety is a concern, think around furnaces, boilers, or certain basement walls, fire-rated sealants like the DAP High Heat Fire Resistant Mortar are a smarter choice since they're designed to hold up under heat without crumbling. For oversized cutouts where pipes or cables run through, a rubber grommet can be a cleaner solution. It creates a snug fit around the line and closes off the excess space. Besides, it allows access if you ever need to service that utility, which is a plus.