Reviewed by William "Willy" Vizcarrondo, NYS DEC Certified Commercial Pesticide Applicator C1825832. Updated September 23, 2026.
Short answer
Slowly, but for a long time before you notice. A single colony doesn't level a house in a season; the problem is that University of Kentucky's extension notes infestations can go undetected for years, so by the time a swarm or a soft board gives them away, the damage has been accumulating quietly. Penn State notes termite problems usually show up 10 years or more after a house is built.
Years, not weeks. A new colony starts with a single mated pair after a swarm, and UC IPM notes it may reach only about 75 individuals after its first year. It takes years to grow into the mature colony of hundreds of thousands that does real damage, and Penn State's observation that termite problems usually occur 10 years or more after construction reflects that. The danger isn't speed. It's that termites feed from inside the wood, out of sight, and the outside surface of a sill plate can look fine while the inside is gone. The colony that swarmed in your basement this spring may have been feeding since before you bought the house.
Hollow wood with dirt inside. Penn State describes infested wood as having runways or passages coated with an earth-like material, and when feeding is extensive, wood largely hollowed out with passages and rotten in appearance. UC IPM adds that damaged wood is typically thin at the surface and easily punctured with a knife or screwdriver, and that darkening or blistering of structural wood is another sign. The EPA's advice for finding it is to probe exposed wood for hollow spots with a flathead screwdriver. Sill plates, the bottoms of studs, basement window frames, door jambs at grade and subfloor under bathrooms are where it turns up first, because that's where wood meets soil or moisture.
Time, moisture and how close the wood is to the ground. A colony feeding on a damp sill plate behind a finished basement wall, with a leaking hose bib keeping the soil wet, does more damage in five years than one working on a dry, exposed beam that gets looked at every spring. The EPA's prevention list is about removing those advantages: keep soil around the foundation dry with proper grading and working gutters and downspouts, fix leaks immediately, and don't store firewood or wood debris against the house. Regular inspection is the other half; UC IPM recommends every 3 to 5 years.
Most of the termite damage we open up on Long Island is in houses from the 1950s and 60s, which fits Penn State's 10-year-plus timeline several times over. Slab houses in Levittown, Hicksville and Massapequa hide it under the floor, so the first sign is a swarm at a bathroom or a soft threshold. Houses with basements in Huntington, Smithtown and Babylon show it on the sill plate and the bottom of the basement stairs. A termite inspection finds it before the swarm does, and it's free with an estimate.
Related
Not in any realistic timeframe for a house that's being lived in and maintained. What they do is hollow out sills, studs and joists to the point that floors sag, doors stick and framing has to be replaced, which is expensive carpentry. Decades of neglect is a different story, but that's rare in an occupied home.
Probe and look. Take a flashlight and a flathead screwdriver into the basement or crawlspace and press it into the sill plate, the bottom of posts and any wood near the floor; sound wood resists, damaged wood gives. Look for earth-colored mud tubes on the foundation walls and posts, blistered or dark patches on wood, and small piles of wings near windows in spring.
Usually not, because most policies treat it as preventable maintenance rather than a sudden event. Check your own policy, but plan on the repair being out of pocket, which is the strongest argument for regular inspections.
Still not sure? Call (516) 509-6001 and we'll tell you what you're dealing with.