Spraying a visible ant trail with a store-bought aerosol kills roughly 1% of the colony and, worse, causes many species to "bud" — the colony splits into multiple smaller colonies and comes back stronger. Castle Exterminators uses non-repellent baits and perimeter treatments that workers carry back to the queen, collapsing the entire colony from the inside out. We handle every ant species active in the Durham area, including odorous house ants, pavement ants, sugar/pharaoh ants, Argentine ants, fire ants, and carpenter ants.
The Triangle has an unusually diverse ant population, and species ID is the single most important factor in whether treatment succeeds. Odorous house ants (small dark ants that smell like rotten coconut when crushed) are by far the most common indoor ant in Durham — they follow moisture and sugar, and their colonies can contain hundreds of queens across multiple satellite nests, which is why repellent sprays make them worse.
Carpenter ants (large black or reddish-black ants, up to a half-inch long) don't eat wood but do excavate it for nesting, causing real structural damage over time; they need a fundamentally different treatment approach than nuisance ants.
Pavement ants nest under driveways, walkways, and slab foundations — nuisance-level but persistent. Argentine ants form supercolonies that can span an entire neighborhood, which is why one house treating alone often struggles. Fire ants (imported red fire ants, Solenopsis invicta) build outdoor mounds and deliver aggressive stings that trigger serious reactions in sensitive people — the CDC estimates 5% of the population reacts significantly.
Pharaoh and sugar ants are tiny, indoor-only, and require specialized bait protocols because they cannot be killed with contact sprays without triggering budding. Every ant job we take starts with correct species ID and a walk-through, and every quote is personalized before treatment.
Our ant treatment process, step by step
Step 1 — Free inspection and species ID. A licensed technician walks the interior (kitchen, bathrooms, laundry, wherever you've seen activity) and the exterior perimeter (foundation, mulch beds, tree stumps, retaining walls, eaves, wall-to-slab transitions). We collect specimens to confirm species — some ants look nearly identical to the eye but require completely different treatments. Species ID drives everything that follows.
Step 2 — Personalized written quote. Based on species, number of active trails, whether nests are indoor / exterior / structural, and whether we're dealing with a single colony or a supercolony network, you get a written scope: bait products, perimeter approach, follow-up schedule, and warranty terms. No flat rates.
Step 3 — Non-repellent bait deployment. Non-repellent liquid or gel baits are placed directly on active trails and at colony entry points. Workers feed on the bait, don't die immediately, and return to the nest — where they feed the bait to the queen, brood, and other workers via trophallaxis (mouth-to-mouth food sharing). The active ingredient moves through the colony over 7–14 days and the entire population collapses, queen included. This is dramatically more effective than any repellent spray, and it's the only approach that reliably works on multi-queen colonies.
Step 4 — Exterior perimeter barrier. Non-repellent liquid treatment applied to the foundation perimeter, eaves, wall-to-slab transitions, and around utility penetrations. This creates a zone where foraging ants pick up the active ingredient and carry it back — a slow, colony-collapsing effect rather than a quick-kill barrier that just pushes ants around the outside of the home.
Step 5 — Species-specific treatments. For carpenter ants, we locate and directly treat the parent colony (typically in a moisture-damaged wood area — deck framing, window casing, wall void — often traceable to a roof leak or plumbing issue). For fire ants, we combine mound drenches with broadcast bait for yard-wide reduction. For pharaoh/sugar ants, we use ultra-targeted bait stations and specifically avoid any product that could trigger budding. The species dictates the specific tools.
Step 6 — Follow-up and monitoring. We return 2–3 weeks after initial treatment to confirm zero activity. For homes near woods, mulch beds, or ant supercolony pressure, we recommend enrollment in the quarterly General Pest Control program to maintain an exterior perimeter that prevents new colonies from establishing.
Why sprays make ant problems worse (colony budding)
This is worth being specific about because it's the #1 reason DIY ant control fails. Repellent sprays (most consumer aerosols, most granular ant killers, most "kills on contact" products) do exactly what the label says — they kill ants on contact and repel other ants from that area.
The problem: for odorous house ants, pharaoh ants, ghost ants, Argentine ants, and several other common species, colonies respond to stress by budding — the colony splits, secondary queens carry brood to new nesting sites, and one colony becomes three or four. The visible trail disappears for a week, then reappears in three new locations. Two months of DIY spraying can turn one manageable colony into a whole-house infestation.
Non-repellent baits work opposite: workers don't detect them, don't change behavior, don't bud the colony. They carry the bait home, feed the queen, and the colony dies without ever knowing it's being treated. Slow (7–14 days) but permanent, and it doesn't multiply the problem.
Carpenter ants — the ones that damage your home
Carpenter ants are the one ant species where the treatment plan pivots hard toward structural investigation. Unlike termites, carpenter ants don't eat wood — they excavate it to build galleries for nesting, preferring wood that's already softened by moisture. Which means: where there are carpenter ants, there is almost always a moisture issue.
Typical carpenter ant colonies in Durham homes are traced to leaking roof flashings, poorly caulked window frames, plumbing leaks in wall voids, deck framing exposed to rain, and crawl-space moisture. Treating the ants without finding and fixing the moisture source guarantees they come back — often within a year — and the structural damage continues.
Our carpenter ant program includes moisture assessment during the inspection. If we find a leak or moisture source, we'll flag it in writing and recommend appropriate repair (which may need a general contractor or handyman — we don't upsell repair work we're not qualified for). Long-term carpenter ant prevention is 30% treatment and 70% moisture control.
Fire ants — the yard problem with a health component
Imported red fire ants (Solenopsis invicta) build the loose sandy mounds you see in Durham yards, typically 4–18 inches across. Contrary to appearance, the mound itself is only the visible top of a colony that extends 3–4 feet underground and can hold 200,000+ workers with multiple queens. Stepping on or disturbing a mound triggers coordinated aggressive stinging — dozens of ants can bite within seconds. The CDC estimates 5% of the population reacts significantly to fire ant venom, and about 1% has serious enough reactions to warrant medical attention.
Effective fire ant control combines two products: mound drenches (targeted liquid treatment poured directly on visible mounds — kills that colony within 24 hours) and broadcast bait (granular bait applied to the entire lawn on a schedule — foragers carry it back to hidden colonies you can't see). Doing one without the other is why "I treated the mound and they came back next door" is such a common complaint. We do both.
Why every ant quote is personalized
A single-species interior odorous house ant trail in one kitchen is a very different job than a whole-property carpenter ant colony traced to a roof leak, or a yard-wide fire ant infestation, or a multi-species mixed indoor/outdoor problem. Species, colony count, whether we're treating for structural (carpenter) or health (fire) or nuisance (everything else) reasons, and whether the property has ongoing exterior pressure from woods or supercolony neighbors all change the scope significantly.
Flat "ant treatment" rates are almost always wrong for the actual job. We walk the property, ID the species, and personalize the quote before we treat.
Common signs you need help
- Trails of ants leading to food, water, pet bowls, sinks, or trash cans
- Small piles of sawdust-like frass or wood shavings near baseboards, window frames, or deck framing (carpenter ants)
- Visible mounds in the yard, driveway cracks, or patio joints (fire ants, pavement ants)
- Winged ants ("alates") emerging inside the home in spring — the sign of a mature indoor colony
- Bites or stings around outdoor mounds, especially aggressive coordinated stings from disturbed nests (fire ants)
- Ants trailing along a wall-to-ceiling line — usually indicates a colony inside the wall void
- A faint rotten-coconut smell when ants are crushed (odorous house ants — the #1 indoor species in Durham)
- Recurring ant activity in the same spot despite repeated DIY sprays — a classic budding signature
How Castle Exterminators handles it
Free inspection + species ID
Licensed technician walks interior and exterior, collects specimens, and confirms species. Different ants require completely different treatments — species ID is where DIY fails and pros succeed.
Personalized written quote
Products, method (bait vs perimeter vs structural), follow-up schedule, and warranty in writing. Personalized to your infestation and species. No flat rates.
Non-repellent bait transfer
Workers carry slow-acting bait back to the queen and brood via trophallaxis, collapsing the entire colony in 7–14 days without triggering budding.
Exterior perimeter barrier
Non-repellent liquid on foundation, eaves, and utility penetrations creates a zone where foragers pick up active ingredient and carry it home — colony-collapsing rather than surface-repelling.
Species-specific treatment
Carpenter ants: locate and treat the parent colony + moisture-source assessment. Fire ants: mound drenches + broadcast bait for yard-wide control. Pharaoh/sugar ants: bait-only protocol to prevent budding.
Frequently asked questions
Why did spraying make my ant problem worse?
Most consumer sprays are repellents. For odorous house ants, Argentine ants, pharaoh ants, and several other common species, colonies respond to repellent stress by "budding" — splitting into multiple smaller colonies with new queens. What was one visible trail becomes three or four new colonies in different parts of the home. We use non-repellent products that ants don't detect — they carry them home to the queen instead of scattering.
Do you treat fire ant mounds outside?
Yes. Effective fire ant control combines mound drenches (targeted treatment poured directly on visible mounds — kills that colony within 24 hours) with broadcast bait applied to the entire lawn (foragers carry it to hidden colonies you can't see). Doing one without the other is why fire ants "come back next door" — we do both.
How much does ant control cost?
Price depends on species, whether the colony is indoor / exterior / structural (carpenter), how many colonies are active, and whether you have ongoing exterior pressure from woods, mulch beds, or supercolony neighbors. A single interior trail is not the same job as a whole-property carpenter ant issue, so we don't publish a flat rate. Walk-through and quote are free — you get a personalized number in writing before treatment.
How long until the ants are gone?
Non-repellent baits work over 7–14 days — you may see MORE ant activity in the first 2–3 days as workers actively transport bait back to the nest. Full colony collapse typically completes within 2 weeks. Multi-queen or supercolony situations may need one follow-up treatment.
Do I have carpenter ants or termites?
Both eat their way into wood, but they leave different evidence. Carpenter ants push out "frass" — small piles of coarse sawdust-like material that also contains ant body parts and debris. Termites produce fecal pellets (drywood termites) or leave mud tubes (subterranean termites — the common NC species). If you're not sure, take a photo of the material and any ants you've seen — we can usually tell you from the photo before we come out.
I have carpenter ants — is there wood damage?
Possibly, and this is worth investigating. Carpenter ants nest in wood that's already softened by moisture, so where there's a colony there's usually a moisture source (roof leak, window flashing, plumbing leak, deck framing exposed to rain). Our inspection includes a moisture assessment; if we find a leak, we'll flag it in writing so you can address the underlying issue. Long-term carpenter ant prevention is 30% treatment and 70% moisture control.
Are the products safe for kids, pets, and pollinators?
Yes. Baits are placed in cracks, crevices, and out-of-reach harborage where kids and pets can't contact them. Exterior perimeter treatments are applied to foundation and structural surfaces, not to flowering plants or pollinator gardens. Products used are EPA-registered per label at residential-appropriate rates.
Will you need to spray inside my house?
For most ant issues we solve interior activity with bait placement (no spraying inside). Perimeter treatment is exterior. If a colony is nesting inside a wall void — most common with carpenter ants — we may inject non-repellent directly into the void, which is a targeted, low-volume application, not a general interior spray.