The Dangers of DIY Pest Control

Most DIY pest control fails for one of three reasons. The product went where the pests are seen instead of where they live, the wrong species was treated, or the treatment scattered the problem instead of controlling it. Prevention work is worth doing yourself. Foggers, wasp nests in walls, bed bugs, and rodents living inside the house are where DIY pest control reliably costs more than it saves.

There is nothing wrong with doing things yourself. Plenty of pest problems are worth handling without calling anyone, and this article says exactly which ones.

But pest control can fail in a way most home projects cannot. A bad paint job only looks bad. A bad pest treatment can spread the problem across the house or turn two weeks of trouble into six months. It can also expose your family to a product used the wrong way. It helps to know the difference before you buy anything.

The pests you can see are not the problem. Many insects and rodents live inside walls, under structures, and in other hollow spaces. Only a small fraction of them is ever out in the open at once. Treating what you can see leaves the population and its source untouched, so the pests come back within weeks and the homeowner decides the product did not work.

Three specific failure modes account for most of it:

• Treating the symptom, not the source. Spraying a baseboard where you saw an ant does nothing to the colony. Removing the spider on the wall does not address the insects it came in to eat.
• Misidentification. Different species need really different approaches. Odorous house ants and carpenter ants call for different treatments, and carpenter ants signal a moisture problem in the structure that no spray addresses. Treating the wrong species wastes both the product and the season.
• Scattering. The most expensive DIY pest control mistake. Certain products, especially aerosol foggers and repellent sprays applied to the wrong pest, push insects deeper into the hollow spaces inside walls and adjacent rooms rather than controlling them. A problem contained in one bedroom becomes a problem in four.

The risk is not that store products are inherently dangerous. It is that they are applied off-label. Federal pesticide law requires application to follow the EPA-approved label, and the label specifies where a product may be used, at what rate, and with what precautions. Most misuse happens because nobody reads it.

Four mistakes are common. People use an outdoor-labeled product indoors, or they apply more than the label rate on the theory that more works better. They treat surfaces that children and pets touch directly. They also mix products, and combining products can create a hazard that neither one carried alone.

Rodent bait carries a second risk, called secondary poisoning. Over-the-counter rodent baits can move up the food chain when a dog, a cat, an owl, or a hawk eats a poisoned rodent. That is a real risk in South Metro Denver, where raptors hunt the open space that many of these neighborhoods back up to.

Licensed applicators in Colorado are trained and regulated on exactly this: which product, at what rate, in what location, with what re-entry interval. That training is most of what you are buying.

Four, in rough order of expense. Each turns a manageable job into a larger one.

Foggers and bug bombs on bed bugs. The most costly single mistake in DIY pest control. Foggers do not reach the cracks and seams where bed bugs actually live, and the repellent effect drives them into the hollow spaces inside walls and neighboring rooms. A one-room problem becomes a whole-house problem, and the treatment cost multiplies accordingly.

Wasp and hornet nests inside structure. A nest in a hollow space inside a wall, a soffit, a hollow metal railing, or under deck stairs is not a can-of-spray job. Partial treatment produces defensive insects and a partially killed colony that rebuilds, plus a real sting risk during the attempt. Nests inside structure also leave material behind that attracts secondary pests.

Rodent bait placed without sealing the entry points. Bait without sealing the entry points means new rodents keep arriving. It also means rodents die inside the hollow spaces inside walls, which produces an odor problem that has to be located and opened up.

Repeated partial treatments over months. The slow, expensive version. Buying product every few weeks for six months usually costs more than one professional treatment would have, and the problem is larger at the end than at the start.

If you are somewhere in the middle of one of these, stopping is the cheapest move available. Call Guardian Pest Management at (303) 346-7087 and describe what you have tried; that tells us more than the pest alone does.

Most prevention work is good DIY pest control, and it is the part that matters most. You do not need a license, a pesticide, or a professional for any of it. Done well, it reduces how often you need anyone.

• Seal entry points: gaps larger than a quarter inch packed with copper mesh, then caulked over
• Fix moisture: leaking spigots, downspouts discharging at the foundation, damp crawl spaces
• Keep landscaping, mulch, firewood, and stored items about two feet clear of exterior walls
• Trim branches back from the roofline
• Switch exterior white bulbs to warm-toned ones to pull fewer flying insects
• Store pet food, birdseed, and pantry goods in hard containers
• Manage standing water: gutters, saucers, toys, tarps, and low spots
• Vacuum spider webs and egg sacs, and empty the canister outside

Beyond prevention, a few treatment jobs are fair to do yourself:

• One wasp nest you can see, out in the open, on a surface you can reach from the ground. Treat it at dusk with a product labeled for it.
• Ant bait stations, used the way the label says.
• Snap traps for a single mouse, when you already know the entry point and have sealed it.

Here is the line. Prevention and small, contained problems are yours. Call someone with a license for anything inside a structure or anything involving bed bugs. The same goes for anything you cannot identify, and for anything that has not responded to one good try.

If you are not sure which side of that line you are on, call (303) 346-7087 and describe it. The call is free, and we would rather answer your question than treat something you could have handled.

Guardian Pest Management is family owned. Sean and Michelle Meade have run it since 2000. We serve Highlands Ranch, Littleton, Castle Rock, Parker, Centennial, Lone Tree, Castle Pines, Greenwood Village, Roxborough, and Cherry Hills. Sean and Michelle personally bring more than 30 years of pest control industry experience, earned before Guardian was founded. That was earned before Guardian opened. We hold a 5.0-star Google rating in South Metro Denver.

We use EPA-registered products applied according to label instructions, by licensed technicians. It is the same rule this article asks you to follow at home.

We also tell people not to buy things. Say you call about a single wasp nest you can reach from the ground, or one mouse and a gap you have already found. We will tell you that you can handle it. Home service does not require a long-term contract, so a one-time visit is a real option and we have no reason to turn a small problem into a plan.

If a DIY attempt has stalled, or you would rather have it identified correctly the first time, call Guardian Pest Management at (303) 346-7087, or start at myguardianpest.com.

Related reading: Secondary poisoning, and what it means for pets and wildlife; How to keep rodents out of your home; Finding and treating bed bugs at home; When a pest problem is worth calling about.