- (301) 829-0060
- Mt. Airy, MD
- info@pestshieldinc.com
Pest Shield has been treating ant problems across Frederick County since 2011, licensed by the Maryland Department of Agriculture (MDA #30263) with a certified entomologist on staff. Owner Troy Yowell brings roughly 35 years of pest management experience, including years protecting U.S. military bases overseas, and personally handles the majority of service calls. The company holds a 5.0 rating across 338+ reviews and was named Best of Frederick, MD Pest Control in 2021 and a Best of Nextdoor pick four years running (2021–2024).
How it works
Four steps. No surprises. Same answer whether it's your first call or your tenth.
You reach Troy or someone on his team directly. No call center, no dispatcher, no routing.
Same-day or next-day for most calls. Emergency stinging-insect situations and real-estate WDI deadlines get priority.
We identify the species, locate entry points, and find the source — not just the symptom.
Written recommendation, straightforward pricing, no obligation. If you don't need treatment, we'll tell you.
The signs of an ant infestation usually show up in predictable places — kitchen counters, around sinks, along basement floors, near window frames, or on garage slabs. What looks like a handful of ants is rarely the whole problem. Visible ants are foragers; the colony is somewhere else, often inside a wall void, under a slab, or in damp wood nearby. Identifying which species you’re dealing with is the first step toward actually solving it, because the three ants Frederick homeowners see most often behave very differently.
Frederick’s mix of historic downtown homes, mid-century neighborhoods, and newer subdivisions on the city’s edges creates consistent ant pressure each year, typically picking up in March and peaking through early summer. Older stone and brick foundations offer natural entry points; newer construction on heavier clay soils tends to support larger pavement ant colonies. Carpenter ant pressure is higher in wooded neighborhoods near the Monocacy River corridor and along Catoctin Mountain’s eastern edge. A single treatment can knock down what you see, but if the conditions producing the colony are still there — moisture, entry points, food access — the activity comes back. That’s why species identification and source location matter more than spray volume.
60+ years of combined experience. Tell us what you’re seeing — we’ll come look, no obligation.
Pavement ants raided our basement this morning and I was desperate for someone to come today! After calling around and being told they recommended a quarterly service before even seeing our problem and couldn’t come out until Thursday(!!!) I called pest shield and they came this morning. He explained the problem and found the source. He sprayed the area and around the house and doesn’t think we need a service plan. He is also knowledgeable about mosquitoes. Call them!!
Elise Richard · June 2024 Read on Google →
moved in to a new house and discovered ants. Another company couldn’t get rid of them. Troy got rid of ants very quickly – haven’t seen them since he began treating the house.
Melissa Evans · April 2015 Read on HomeAdvisor →
Troy is awesome. He educated us on what variables we had in our house and yard that were creating an ant-friendly environment so that we can get rid of all factors contributing to our horrific ant infestation. And his products work…he is right, there is not enough bait in the world to get rid of a well established ant colony!
Meagan Simpson · June 2015 Read on HomeAdvisor →
General pest & rodent control
Pest Shield starts every new ant job with a free inspection. Troy or one of the technicians identifies the species, locates the colony source, and looks at the entry points and conditions that produced the activity in the first place. When field identification isn’t conclusive, samples go to on-staff entomologist Jeffrey Allwine for laboratory ID. Only after that assessment does treatment get recommended — and sometimes the recommendation is that a single visit will solve it. One Frederick-area customer wrote that other companies “recommended a quarterly service before even seeing our problem”; Pest Shield came out the same morning, treated the pavement ants, and said a service plan wasn’t needed.
Treatment is exterior-first by design. The perimeter of the home gets treated to interrupt foraging trails and target the colony at the source, with interior application limited to where it’s actually needed. This approach keeps chemical use out of living spaces when possible — important for families with children, pets, or anyone sensitive to indoor pesticide application. EPA-approved products are standard, and nontoxic bio-pesticide options are available for homes where reduced-risk treatment is the priority.
For homeowners who want ongoing protection — particularly in neighborhoods with high seasonal pressure or wooded surroundings — Pest Shield offers the Standard Care Plan: treatment every 60 days (more frequent than the industry-standard quarterly), a 100% effective guarantee, and free service between scheduled visits if pest activity reappears. The bi-monthly cadence is calibrated to interrupt colony cycles before infestations re-establish, and you don’t need to be home for treatment. The plan also covers spiders, cockroaches, crickets, silverfish, water bugs, centipedes, and other general pest pressure — which makes it a reasonable fit for many Frederick homes, but Troy will tell you straight if a one-time treatment is the better call. That honesty is the most cited reason customers stay with the company.
Owner
Founded Pest Shield in 2011 after years as a pest management contractor on U.S. military bases in Iraq and Afghanistan. Around 35 years in pest management. Personally handles or leads the majority of service calls.
Pest Management Specialist
Field technician handling residential and commercial service calls across Frederick, Carroll, and Montgomery counties.
Pest Management Specialist
Field technician handling residential and commercial service calls across the service area.
Our Entomologist
Consulting entomologist on species identification, conducive conditions, and treatment strategy for difficult cases.
Frederick sits at the junction of I-70 and US 15, where the Monocacy River cuts through farmland east of Catoctin Mountain and the city’s historic downtown gives way to newer subdivisions toward Urbana, Walkersville, and New Market. Pest Shield serves homes across Frederick County, from the older neighborhoods near Baker Park to the wooded developments along the Catoctin foothills.
Frederick’s housing mix matters for ant pressure. Older homes in the historic district often have stone or brick foundations with natural gaps that pavement ants and odorous house ants exploit. Newer subdivisions east and south of the city sit on clay-heavy soils that hold moisture against foundations — ideal conditions for large pavement ant colonies. Wooded lots near the Monocacy corridor add steady carpenter ant pressure to that mix, making pest control in Frederick a year-round concern for many homeowners.
It depends on the species, the source, and the conditions around your home — and Pest Shield will tell you straight which one fits. For an isolated pavement ant problem or a localized odorous house ant trail, a single targeted treatment is often enough, and Troy has been documented recommending against a service plan when one isn’t needed. For homes with wooded surroundings, recurring seasonal pressure, or carpenter ant activity near structural wood, the Standard Care Plan (60-day cadence, 100% effective guarantee, free retreatment between visits) is the more reliable option. The free inspection is where that call gets made.
Carpenter ants don’t eat wood, but they excavate it to build nests — and over time, that tunneling can weaken structural framing, window sills, door frames, and porch posts. They prefer wood that’s already damp or softened, so their presence often points to a moisture issue worth addressing alongside the ants themselves. In Frederick, carpenter ant pressure is higher in wooded neighborhoods and around older homes with any history of roof or gutter leaks. Treatment targets the colony and addresses the conditions that drew them in.
Size and location are the easiest tells. Pavement ants are small (about 1/8 inch), dark brown, and almost always found at ground level — pushing soil through basement floor cracks, along garage slabs, or at concrete expansion joints. Carpenter ants are much larger (1/4 to 1/2 inch), usually black or reddish-black, and tend to show up around wood: window frames, door casings, porch beams, or roof eaves. If you’re seeing small piles of what looks like sawdust, that’s almost always carpenter ant frass. When field ID isn’t clear, Pest Shield sends samples to entomologist Jeffrey Allwine for confirmation.
Yes. Pest Shield uses EPA-approved products and prioritizes an exterior-first treatment approach — the perimeter of the home gets treated, which keeps chemical application out of living spaces when possible. For families that want the lowest-impact option, nontoxic bio-pesticide alternatives are available. Customers with immunocompromised children and homes with dogs have specifically called out the company’s care around safety in their reviews. If you have concerns about a specific area — a play space, a pet feeding zone, a vegetable garden — mention it during the inspection and the technician will adjust accordingly.
Usually same day or next day for Frederick-area homes. Calls go directly to Troy, the office, or a technician — not a dispatcher or call center — so scheduling happens on the first conversation. Same-day Sunday service has been documented at no extra charge, and after-hours visits are accommodated when the situation calls for it. Call (301) 829-0060 to schedule a free inspection.
