Visible mud tubes running up the exterior foundation wall
Tools: flashlight, putty knife, awl or screwdriver, phone camera, tape measure · Materials: none — treatment is professional work in most places
Steps
- Photograph every tube with something for scale, then break a 5 cm (2-inch) section out of one tube and check it in a few days: a repaired tube means the colony is active.
- Walk the whole perimeter, the crawl space and the garage, and note every tube, every piece of wood touching soil, and every spot where mulch or soil sits above the top of the foundation.
- Probe the sill plate and the framing where a tube reaches wood; a screwdriver that sinks in or a hollow sound means feeding has started.
- Pull mulch, soil and firewood back at least 15 cm (6 inches) below the top of the foundation and away from any wood, and remove wooden form boards or stumps in contact with the house.
- Fix the moisture the termites came for — a dripping tap, a downspout at the wall, a wet crawl space.
- Book an inspection now: subterranean termite treatment is a licensed job almost everywhere, and the earlier the barrier or baits go in, the less wood they eat.
Stop and call a pro if
- always — any active tube is a call to a licensed pest-control company; your part is the inspection, the moisture and the wood-to-soil contact
- framing sounds hollow or a probe sinks in — a carpenter's assessment comes with the treatment
- you find swarmers or discarded wings indoors
Rules in the US: Termiticides are restricted-use in most states; a licensed applicator applies the soil barrier and issues the treatment record lenders ask for at resale.
Rules in Spain: El tratamiento contra termitas lo realiza una empresa inscrita en el ROESB; el propietario puede corregir la humedad y el contacto madera-suelo.
What a pro does that you can't
A licensed pest-control technician identifies the species, installs a liquid barrier or bait stations around the perimeter, and monitors until the colony is gone; a carpenter replaces framing the termites have hollowed.
DIY cost: $0 — inspection and housekeeping only