Structural and Carpenter Ant Damage

• Locate frass: coarse shavings mixed with insect fragments, distinct from termite pellets or drywood debris.
• Sound the wood. Hollow, papery resonance and smooth galleries that follow the grain indicate excavation.
• Track moisture with a meter around window and door headers, sill plates, roof valleys, chimney flashing, tubs and shower pans, and any deck ledger.
• Work at dusk. Carpenter ants forage at night, and watching the line for 20 minutes after sunset is often faster than an hour of daytime probing.
• Distinguish parent nest from satellite. Parent nests contain the queen and brood and are usually in wet wood or an outdoor tree, stump, or landscape timber.

1. 01

   Fix the water

   Repair the leak, correct the flashing, extend the downspout, improve ventilation in the crawl space or attic. Untreated moisture guarantees re-infestation regardless of what was applied.

2. 02

   Locate and treat the nest directly

   Void injection with a non-repellent dust or foam into the actual gallery is the highest-value treatment in carpenter ant work. Drill patterns should follow sounded voids, not guesswork.

3. 03

   Bait the foraging line

   Where the nest cannot be located, protein or sugar gels placed on the nocturnal trail can reach the parent colony. Carpenter ants shift preference seasonally, so run both and watch which recruits.

4. 04

   Trim the bridges

   Cut back branches touching the roof and siding, remove firewood stacked against the wall, and pull mulch and landscape timbers back from the foundation. Most satellite nests arrive by a physical bridge.

5. 05

   Remove and replace compromised wood

   Galleried structural members that have lost section need replacement, not treatment. This is a construction fix, and it should be documented as such.

Reinspect at 30 days and again at the next spring swarm window. New frass in a previously cleaned area is the definitive indicator that a nest survived.