Which pests cause the most expensive repairs?

This is the one question in the hub where the honest instinct is to reach for a number, so it's worth explaining why we don't. Ranking pests by repair scope and structural consequence tells you something durable: does the fix require a licensed contractor to rebuild framing, or a rag and five minutes? Ranking by a dollar figure tells you something that changes by contractor, by region, and by year — and in this specific subject, the dollar figures in circulation are themselves the problem.

The most repeated cost statistic in pest control is the claim that termites cause a multi-billion-dollar figure in annual damage — 'more than fires, floods, and storms combined.' That line comes from the National Pest Management Association, and it's a pest-industry estimate, not a government damage survey; a trade-press investigation found it was extrapolated from insecticide-sales data and repair-to-treatment cost ratios, not measured losses. The peer-reviewed number it gets confused with, from a 2012 study in the Annual Review of Entomology, is a global total — and roughly 80 percent of that figure traces to species dominance data, with a large specific share attributed by university entomologists to the Formosan subterranean termite, a species that is not established in New Hampshire. So even the number people think they know is measuring the wrong bug in the wrong place. We rank by repair scope instead, because that's the part that's actually verifiable.

Three pests on this list can genuinely require a licensed contractor, and all three share a timescale people underestimate: years, not weeks. Eastern subterranean termites — the only termite species established in New Hampshire — feed continuously but slowly; Penn State Extension puts serious structural damage at 'usually 10 years or more' of ongoing feeding, not a sudden onslaught. Carpenter ants don't eat wood at all; they excavate galleries in wood that's already softened by a moisture problem, and University of Maryland Extension notes their nest sites 'rarely exceed a few square feet' — the ants are usually a symptom, and the leak is the actual defect. Powderpost beetles work hardwood flooring, sills, and cabinetry over multiple generations; Purdue Extension calls them second only to termites among destroyers of seasoned wood, but a light infestation is often a watch-and-dry situation rather than an emergency tear-out.

What unites all three: the repair, when it's needed, is a contractor's job — framing, sills, or flooring — and Anchor's role is stopping the pest, not swinging the hammer.

Raccoons don't need years. A raccoon looking for a denning site can tear open a soffit, rip up shingles, or widen a roof vent in a single night, and once inside it fouls insulation and can chew wiring. That single entry event typically spins up three separate trades: a roofer for the building envelope, a wildlife-exclusion specialist to remove the animal and seal the entry for good, and a remediation crew if the resulting droppings warrant professional cleanup. It's arguably the most expensive-per-incident item on this list precisely because it compresses so much repair scope into so little time — and it gets a fraction of the attention termites do.

Rodent gnawing on wiring deserves care in both directions, because it's the calibration this hub is built to make. The mechanism is genuine: a mouse or rat's incisors grow continuously and must be worn down, they strip insulation off whatever wire is convenient, and an exposed, energized conductor is a recognized ignition source in forensic fire investigation. That part is well documented and it's why chewed wiring gets an electrician, not a shrug.

What isn't documented is the number attached to it. You'll frequently read that rodents cause roughly a quarter of all house fires — usually 'fires of unknown or undetermined origin.' No fire authority publishes that figure. The earliest traceable appearance is an October 2012 trade-magazine article written for the pest industry, which introduced the estimate with no citation and no methodology. NFPA's own research on home fires caused by electrical failure or malfunction identifies arcing as the leading ignition factor and names no rodent factor at all; NFPA's only animal-related home-fire figure is that pets and wild animals combined have a part in a few hundred home fires a year nationwide — nowhere near a quarter of the much larger pool of undetermined-cause fires. And the fire-data system fire investigators actually use has no 'rodent' or 'animal' cause-of-ignition code to begin with, so any percentage attributed to rodents is an extrapolation, not a tabulated statistic. The mechanism is real. The number is invented. If you have chewed wiring, that's a genuine reason to call an electrician — the viral statistic is not the reason.

The pests that generate the most anxious searches are, structurally, the cheapest items on this ledger — because there's nothing to repair. Bed bugs are obligate blood-feeders; they don't chew, bore, or weaken anything, and any 'value' story around them is about stigma and disclosure, not a damaged house. Cockroaches occasionally foul or short a warm appliance, but their better-documented harm is an allergen that triggers asthma, not a repair bill. Spiders cause no property damage of any kind. None of these belong anywhere near the top of a genuinely cost-ranked list, and putting them there is exactly the kind of fear-led ranking this page exists to correct.