- (301) 829-0060
- Mt. Airy, MD
- info@pestshieldinc.com
Pest Shield, Inc. has served Frederick County homeowners since 2011, with MDA license #30263 and over 75 years of combined pest management experience across the team. Owner Troy Yowell has approximately 35 years in the industry and is personally involved in the majority of stinging insect calls — he’s named in more than 30 yellow jacket reviews alone. Pest Shield carries Maryland certified applicator credentials (#19058) and has earned Best of Frederick recognition and four consecutive Best of Nextdoor awards (2021–2024), backed by 338+ five-star reviews across Google and HomeAdvisor.
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.
Yellow jackets (Vespula and Dolichovespula spp.) rarely announce themselves until the colony is well established. By the time you notice workers streaming in and out of a gap in your siding, a crack near a foundation, or a hole in the ground near a walkway, the nest inside may already hold thousands of workers — and late summer is when that number peaks.
Here’s what the signs typically look like, and why each one matters:
Late August through October is the most dangerous window. Colonies reach their largest size — sometimes tens of thousands of workers — just as natural food sources dwindle. Workers become more defensive and unpredictable, and the risk of a serious encounter rises sharply. Emmitsburg’s mix of older farmhouses, agricultural outbuildings, and wooded lots along the base of Catoctin Mountain gives yellow jackets abundant nesting habitat in structural gaps and ground cavities that are difficult to spot and harder to reach.
Structural nests — inside wall voids, behind siding, in exhaust fan vents or chimney areas — are not a DIY situation. The entry point you can see is rarely a reliable indicator of the nest’s size or location. Spraying a consumer product into the opening or attempting to seal it before treatment can trap thousands of workers inside and drive them through interior walls into living spaces. Professional treatment locates the nest, treats it completely, and manages the returning workers that weren’t present at the time of treatment.
60+ years of combined experience. Tell us what you’re seeing — we’ll come look, no obligation.
My wife and I discovered a yellow jackets nest in our siding had moved inside our bedroom wall. Bees were starting to come into the bedroom through the baseboards and window. We called a few large companies first who tried to sell us on an initial price followed by 7 months of service. We’re glad we called Troy at Pest Shield. He gave us a low quote and even stood by it after noticing we had one of the larger nests he had come across this year. Troy was professional going over everything he was going to do while providing us options. We are no longer hearing bees in the wall and the outside activity has dwindled to a bee here or there. Nothing is choosing to go back where Troy sprayed. We really appreciate being bee free again.
djsportbike · August 2023 Read on Google →
On Saturday afternoon, I noticed what looked like the beginning of a water leak in my bedroom ceiling. However, when I got up to inspect it, my finger went right through the drywall and yellow jackets started pouring out. Thank goodness Troy was willing to come out on a Sunday to deal with this so we could get the use of our bedroom back. (My husband is highly allergic so having them inside the house was a health hazard.) Troy was punctual, explained what would happen and dealt with the little beasts very swiftly even though he said it was the largest nest he’d seen in his 35 years in the business. His price was reasonable. He refused to charge us extra for coming on a Sunday and for dealing with what turned out to be a huge nest. I’ve used Troy in the past for other pest management issues. He is honest, reliable and always solves our problems. I highly recommend Pest Shield, Inc. for all your pest issues.
Loretta Usilton · August 2024 Read on Google →
HIGHLY RECOMMEND!! Troy was very professional, honest & his work was effective! Our home is under contract and we had to ensure our yellowjacket issue was resolved with little to no damage done. After many failed treatments with another company resulting in the bees getting inside our walls, we decided to find an expert. The Google reviews speak for themselves! TROY is the real deal! Super responsive, educated us on all the possibilities of our issue, treatment & possible results. Warranty is great even though so far we have no need to use it thus far. He even called to check on us after his treatment to ensure everything was resolved. Good customer service is hard to come by but Troy provided AMAZING customer service! Don’t waste your time or stress call Troy!
Kaylin Gonzalez · August 2023 Read on Google →
General pest & rodent control
Same-day response is the standard for active yellow jacket situations — not a premium add-on. When you call (301) 829-0060, you reach the people who will do the work. Troy Yowell handles the majority of stinging insect calls personally, and he’s documented arriving within hours of a morning call, accommodating after-hours situations, and coming out on Sundays at no extra charge when a nest poses an immediate risk. For households with a family member who is allergic to stings, that response time matters.
The treatment process for a structural yellow jacket nest:
Yellow jacket removal at Pest Shield, Inc. is a single-visit service backed by a seasonal warranty. If the nest reactivates or workers return to the same location within the warranty period, Pest Shield comes back at no charge. There’s no ongoing service plan attached to this work — the job is complete when the colony is gone.
Treatment involves professional-grade pesticide application. Troy uses EPA-approved products and advises on precautions for family members and pets before and after treatment — including how long to stay clear of the treated area and what to watch for. Eco-friendly treatment processes are available. If you have specific concerns about chemical exposure near a garden, food prep area, or a family member with sensitivities, mention it when you call — Troy addresses those situations directly.
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.
Emmitsburg sits at the northern tip of Frederick County, near the Pennsylvania border and the foot of Catoctin Mountain. The town is served by US-15, which connects it south to Frederick and north toward Gettysburg. Pest Shield is based in Mt. Airy and serves all of Frederick County — same-day response applies to Emmitsburg as throughout the service area.
The property character here — older farmhouses, agricultural outbuildings, barns, and wooded lots along the Catoctin ridgeline — creates favorable conditions for yellow jacket colonies in structural gaps, ground cavities near landscaping, and weathered wood structures. Aging siding, deteriorating trim, and foundation gaps common in older rural homes give Vespula spp. exactly the protected cavities they seek for late-season nesting, which is why nest location in this area often requires more than a visual inspection of the entry point. For broader seasonal pest pressure across the area, pest control in Emmitsburg covers the full range of threats these rural properties face year-round.
The entry point is almost never a reliable indicator of nest size. A gap the width of a finger can lead to a colony of several thousand workers occupying a wall void the size of a basketball or larger — and by late summer, colonies in protected structural locations are often at their peak. The only way to assess the actual nest is a professional inspection that reads the flight pattern and evaluates the structure. Troy has treated nests behind entry points that gave no outward sign of what was inside, including one documented as the largest he’d seen in 35 years of pest management work.
Same-day response is standard for active yellow jacket situations, and Pest Shield has documented same-day service on Sundays at no extra charge when a nest poses an immediate risk to someone with a sting allergy. Call (301) 829-0060 directly — you’ll reach the people doing the work, not a dispatcher. When you call, mention the allergy; Troy prioritizes situations where a sting could be medically serious.
No — do not seal the entry point before treatment. Blocking the opening traps thousands of workers inside the void with no exit. They will find another way out, and that path often leads through interior walls into living spaces. Leave the entry point open and keep family members and pets away from the area until treatment is complete. Troy will advise on what to avoid and for how long when he arrives.
The seasonal warranty covers reactivation at the treated location within the current season — if workers return to the same entry point after treatment, Pest Shield comes back at no charge. As for the following year: yellow jackets don’t reuse old nests, but they may establish a new colony in the same structural void if the entry point remains accessible. After treatment, sealing the gap that allowed entry is a practical step to reduce that risk. Troy can advise on what to address after the colony is gone.
Pest Shield uses EPA-approved products and Troy advises on specific precautions — including how long to keep children and pets away from the treated area — before he begins work. The precaution window varies depending on where the nest is located and how the product is applied; Troy will give you a clear answer for your specific situation when he arrives. Eco-friendly treatment options are available. If you have particular concerns about chemical exposure near a garden, food prep area, or a family member with sensitivities, mention it when you call.
