How a colony travels from the woods to your foundation
A subterranean colony does not target houses. It forages outward through soil looking for cellulose, and it settles wherever it finds a reliable supply. On a typical wooded New Hampshire lot, that supply is everywhere. Stumps left from clearing, root systems decaying underground, buried form boards from the original construction, landscape timbers holding a bed, rotting fence posts and a woodpile that has been sitting since the last cold snap. Each of those becomes a feeding site, and each one puts the colony closer to the house. From a timber four feet off the foundation, reaching the sill is a short tunnel and a shelter tube up the wall. This is why treatment alone sometimes disappoints. A liquid barrier blocks the route, but the colony living in a stump ten feet away is still there, still growing, and still probing for a way past the treated soil. The durable version of the fix removes the feeding sites and blocks the route at the same time.
Decks, porches and the wood you forgot is touching dirt
Ask a New Hampshire homeowner where the wood on their property touches soil and most will say nowhere. Then you walk the yard. Deck posts set into the ground rather than on piers are the classic case. So are stair stringers resting on a dirt landing, lattice skirting buried a couple inches, planter boxes built against the siding, and trellises stapled to the wall with their feet in a bed. Each contact point does two things. It gives a colony a protected route from soil to structure, and it keeps that wood damp enough to soften, which makes it more attractive. The fixes are ordinary carpentry. Set posts on concrete piers with metal standoff bases so end grain stays out of the dirt. Put stringers on a pad. Cut skirting so it stops above grade. Move the planter. If you are already replacing a deck, this is the cheapest moment in the deck's life to get it right, and it also solves the rot problem that would have arrived anyway.
The New Hampshire swarm calendar and what to do that week
Nothing happens above ground from December through March. Soil freezes, foraging retreats, and any colony present is feeding below frost depth or inside a heated basement. April and May bring the thaw and the return of surface activity. Shelter tubes get rebuilt, which makes this the highest-value moment for a walk around the foundation with a flashlight. Late May and June is the realistic swarm window in this state, several weeks behind southern New England. Warm still days after rain are the trigger, and coastal areas warm before inland towns. July through September is the productive stretch for both colonies and contractors. Soil is workable, basements are dry enough to inspect properly, and treatment gets the full benefit of a warm season. October into early November is the last comfortable window for trenching. If you found evidence in September, book it rather than letting the calendar decide for you. The habit worth forming: inspect at thaw, treat before frost.
When a termite finding counts as an emergency
Most termite discoveries are urgent in the sense of scheduling, not in the sense of tonight. There are exceptions. A deck ledger or stair stringer that has lost structural integrity is a genuine safety issue, and people fall through these. If a probe goes into a ledger or a stringer feels soft underfoot, stop using the structure and get it looked at right away. A main girder, a bearing post in the basement or a sill under a load point showing significant damage is the same category. That is a call to a structural contractor as well as a pest company. What is not an emergency: a spring swarm, a mud tube found on a foundation wall, or damage in a section of trim. Those need an inspection and a plan within days or weeks, not the same evening. The honest middle ground is that termites work slowly. What creates urgency is not the insect, it is the load the damaged member is carrying.
After the treatment: what you should keep and check
The job is not finished when the truck leaves, and the follow-through is mostly paperwork and habits. Get documentation. You want the product name, the date, the areas treated, linear feet trenched, drill locations, and a diagram. That file matters at resale and it matters if activity returns and you need to discuss retreatment. Ask about reinspection. On a liquid application, a look every year or two is reasonable in this climate. On a bait system, get the service schedule in writing along with what it costs after the first year, because bait protection continues only while stations are serviced. Then keep the treated zone intact. Tell the pest company before you trench for a sprinkler line, a fence, a patio footing or a utility, because digging through treated soil creates a gap exactly where someone dug. Finally, do the yard work you were told to do. A barrier plus a stump in the side yard is half a solution.