Ant exterminator cost in New Hampshire ranges from $110 to $1,200+ for a one-time treatment depending on species and severity. Light general ant infestations (pavement, odorous house, little black ants) typically run $110–$200. Confirmed carpenter ant infestations cost $250–$500 for moderate jobs and $800–$1,200+ for severe multi-nest cases requiring wall-void drilling. Annual quarterly preventive plans — the dominant structure offered by all major NH operators — run $480–$840 per year and include 4 visits plus a free re-service guarantee. Of 10+ major NH operators researched, none publish list pricing on their websites.
At a Glance
$110–$200
Light infestation, one-time NH
$250–$500
Moderate carpenter ant, one-time
$480–$840/yr
Quarterly preventive plan
8–23×
ROI on Year-1 vs. Year-5 intervention
Bottom line — NH ant exterminator costs in 2026 range from $0 (free inspection) to $1,200+ (severe carpenter ant multi-nest protocol). The key decision points are species confirmation (general vs. carpenter), severity tier (MONITOR / TREAT SOON / EMERGENCY), and one-time vs. quarterly — with the 5-year cost math strongly favoring quarterly for any home with prior ant history, moisture events, or pre-1985 construction.
Answer 3 questions to identify which NH pricing tier applies to your situation. Score totals map to light ($110–$200), moderate ($250–$500), or severe ($800–$1,200+) treatment ranges.
Different ant species carry different pricing tiers and treatment approaches. Confirming species before agreeing to a price prevents overpaying for unnecessary carpenter-ant premium or underpaying for a species that requires specialized treatment.
Species 1
Camponotus pennsylvanicus
Distinguishing feature
Pricing premium: $250–$500 moderate, $800–$1,200+ severe — nest location, drilling, and dust injection required; cost-of-delay 3–5×/year compounds
Species 2
Tapinoma sessile
Distinguishing feature
Light-tier pricing $110–$200; bait-only IPM required — repellent sprays trigger colony scattering (Buczkowski & Bennett 2008); crush test: strong rotten-coconut odor
Species 3
Monomorium pharaonis
Distinguishing feature
Pricing $300+ due to coordinated multi-unit bait protocol — any DIY spray triggers budding, converting one nest into 5–10+ satellites (Feng, Choe & Lee 2025); STOP all sprays immediately
Species 4
Tetramorium immigrans
Distinguishing feature
Light-tier pricing $110–$200; responds well to standard perimeter IPM; DIY first is reasonable — call pro if trail persists 14+ days or spreads to second room
Species 5
Crematogaster cerasi
Distinguishing feature
Moderate-tier pricing $250–$500 when wall nest suspected — requires drill-and-dust; raises heart-shaped gaster in alarm posture; cost-of-delay 1.5×/year if tied to active moisture damage
All five southern NH service counties fall within a single Manchester/Bedford/Nashua/Concord/Portsmouth/Keene labor market with less than 5% city-to-city price variation. Pricing differences come from service-frequency needs and housing risk profiles, not travel costs.
Highest absolute carpenter ant volume in NH. Manchester pre-1940 balloon-framed mill housing plus Nashua pre-1960 stock combined with forested western edge (Bedford, Amherst). 179,933 housing units — approximately 48% of the NH total with Rockingham. Quarterly plan is the dominant value play for any home with moisture history.
Portsmouth's pre-1900 clapboard housing is the oldest dense stock in NH, sitting in USDA Zone 6b — the longest foraging window in the state. Salem, Derry, and Londonderry drive suburban volume. Highest median household income ($120,836) means higher repair exposure at Year-5 structural stages.
Concord's South End and downtown contain extensive pre-1940 wood-framed stock. Surrounding rural towns (Hopkinton, Henniker, Warner) have classic forest-edge properties. Pricing within 3% of Manchester market; service frequency adjusts upward for rural properties near forest edge.
Dover and Rochester both carry substantial pre-1940 mill-era stock, with approximately 22% of county homes built before 1950. UNH-Durham proximity drives institutional-market pharaoh ant cases in multi-unit housing — requiring bait-only IGR protocol rather than standard perimeter spray.
Oldest housing stock of all five service counties: 27.3% built before 1940, with a county median construction year of 1973. Balloon-framed balloon-construction dominates pre-1940 Keene stock, creating uninterrupted vertical stud cavities for satellite nests. Monadnock Pest & Wildlife calls carpenter ants 'the most prolific household pest in New Hampshire.'
Bottom line — All five counties have confirmed moderate-to-extreme carpenter ant pressure. Pricing varies less than 5% across the region — what varies is the recommended treatment intensity and whether a quarterly plan is the baseline vs. an upgrade.
These are the 6 most common diagnostic and treatment moments in a typical NH ant service — from the free inspection that opens the process to the quarterly maintenance visit that prevents recurrence.
The technician walks the exterior foundation perimeter and interior basement, probing sill plates and checking moisture levels. All major NH operators offer free inspections. The written quote you receive should include a Tier 1/2/3 severity classification per the 3-tier urgency framework — ask for this in writing before agreeing to pricing.
Fresh frass — coarse sawdust mixed with insect body parts — accumulating at a baseboard or window sill indicates active gallery excavation within the wall. This is a Tier 2 TREAT SOON indicator per the 3-tier urgency framework, and it moves the pricing tier from $110–$200 light to $250–$500 moderate carpenter ant.
For confirmed carpenter ant wall nests, the technician drills a small port (typically 1/8") at the nest void and injects insecticidal dust (deltamethrin or silica gel) or foam directly into the gallery. This targeted nest injection step is what separates moderate carpenter ant pricing ($250–$500) from general ant pricing ($110–$200).
Fipronil non-repellent solution (0.06% Termidor SC or Taurus SC) is applied as an 18-inch-up / 18-inch-out band around the foundation. Ants cannot detect this chemistry, contact it while foraging, and transfer it back to the colony via trophallaxis. BASF documents 100% colony control at this dilution with 90-day residual ant control.
Professional bait stations (Maxforce FC, Advance 375A, or Intice) are placed on confirmed ant trails and at exterior nest entry points. These are refilled at each quarterly visit. Bait-only IPM is mandatory for pharaoh ants and strongly preferred for OHA — repellent sprays cause colony scattering in both species.
July–August is peak foraging season across southern NH — NH operators report 3–6 week lead times during this window in Manchester and Nashua. The summer quarterly visit includes a full perimeter retreat and interior checkpoint. Homeowners on quarterly plans skip the wait: they have a scheduled visit during the exact highest-demand window.
Three questions determine whether DIY first or pro first is the right spend decision for your ant situation.
Of 10+ major NH pest control operators researched, none publish list pricing on their websites. These 2026 southern NH market ranges are triangulated from Homeyou Manchester data (n=1,653 projects), Angi/HomeAdvisor, GoLocal NH, the Carpenter Ant Guide Northeast benchmark, and verified third-party customer reviews. Use the calculator to estimate your range before calling for a quote.
Home size
Infestation severity
Treatment type
Estimated cost
$119–$268
One-time treatment
Single visit: exterior perimeter band + interior baits if needed; 30-day warranty typical; appropriate for light general ant infestations or first-confirmed carpenter ant satellite
Ranges reflect 2026 southern NH market rates (Manchester/Bedford/Nashua/Concord/Dover/Keene labor market). Carpenter ant jobs carry a $50–$200/visit premium over general ant pricing for nest location, drilling, and dust injection. Wood damage repair ($200–$10,000+) is a separate contractor quote and is not covered by homeowners insurance. Actual quotes vary ±20% by property, season, and operator. Free inspection is the standard first step for all major NH operators.
Borax bait (Terro liquid)
$8–$15 per 6-pack · DIY
Effective for OHA, pavement, little black ants during sweet-feeding phase; minimal effect on carpenter ants outside sweet-feeding window (Tripp et al. 2000, J. Econ. Entomol. 93: 1493)
Indoxacarb gel (DIY)
$30–$45 per 30g tube · DIY
Best DIY choice for carpenter ants — 82% mortality by day 8 against OHA in PCT field study; Hansen (2008) ICUP: 55% field colony-elimination rate on Camponotus; protein matrix matches spring foraging preference
Abamectin protein granule (DIY)
$25–$95 retail · DIY
Top DIY product for carpenter ants — protein-corn-grit matrix matches carpenter ant preference; 0.4 oz/1,000 sqft outdoor band; 55% field colony-elimination per Hansen (2008) ICUP Proceedings
Fipronil non-repellent perimeter (pro)
$250–$500 one-time NH · Professional
Pro gold standard at 0.06% (Termidor SC / Taurus SC); non-repellent transfer effect eliminates colony; BASF documents 100% colony control with 90-day residual; 2 applications max per calendar year per label (p4 §2)
Targeted nest injection (pro add-on)
$300–$600 add-on to perimeter · Professional
Drill-and-dust (deltamethrin or silica gel) or foam injection directly into wall void; 80–95% colony elimination rate in single visit when parent nest correctly located (UNH FS 62; Colonial Pest NH Microgen protocol)
Quarterly preventive plan (pro)
$480–$840/year NH · Professional
4 visits: spring emergence, summer peak, fall pre-winter, winter maintenance; free re-service between visits; industry estimates <5% re-infestation rate on quarterly vs. 10–20% on single one-time treatment (p4 §3)
Eliminate moisture first — repair roof and gutter leaks, improve basement ventilation, and fix plumbing drips. UNH Extension calls moisture elimination the single most important cultural practice: carpenter ants almost exclusively colonize moisture-damaged wood.
Seal utility penetrations, foundation cracks, and gaps around window/door frames with caulk or expanding foam. Workers travel up to 100 yards from a parent colony — sealing entry points interrupts indoor foraging even when the outdoor colony cannot be reached.
Keep vegetation, branches, and mulch from touching the house. Each branch is a bridge that bypasses the perimeter spray band. Trim at least 18 inches of clearance between plants and the foundation.
Store firewood off the ground on a concrete pad, away from the house, and use only what you'll burn in one season. Firewood is one of the most common parent-colony origin sites in New England.
Remove dead tree stumps within 100 feet of the foundation. UNH Extension explicitly lists stump elimination as a preventive measure — outdoor colonies in stumps are the leading source of indoor satellite nests.
Schedule an annual spring inspection by April 1 in southern NH — before the May–June primary swarm window. Pre-emergence inspection catches Year-1 satellites before worker populations peak, keeping the problem in the $250–$600 range rather than the $1,600–$4,000+ Year-3 range.
Of the 10+ major NH pest control providers researched — Modern, JP, Colonial, Garfield, Anchor, Fox, Ehrlich, Precision, NW, Dependable, Insight, and Aptive — none publish list pricing on their websites. All require a free inspection before quoting. The only firm price data from named NH operators come from third-party reviews: Insight Pest Solutions Manchester Angi-verified at $129 for a wasp/ant single visit; Identify Pest Control Manchester at $250 on Yelp for a one-time treatment. Publishing the full 2026 pricing ladder is itself a trust differentiator in a market where opacity is the norm.
Key Local Data
Hillsborough and Rockingham counties together contain approximately 316,614 housing units — about 48% of NH's total stock — making southern NH the highest-volume carpenter ant service market in the state.
Most NH operators hide pricing. We publish the full 2026 ladder — and back it with a free inspection, written severity classification, and 30-day follow-up included in every moderate and severe treatment.