Carpenter Ants
The #1 structural threat to Northwoods lake homes
About Carpenter Ants
Carpenter ants are the most destructive pest in the Northwoods. Unlike termites, they don't eat wood — they excavate it to build their nests, leaving behind smooth tunnels and galleries that weaken structural beams, window frames, decks, and sills. A mature colony can contain thousands of workers and cause tens of thousands of dollars in damage before the homeowner even notices.
How to Identify Them
- Large black ants, typically ¼ to ½ inch long — the biggest ants you'll see in Wisconsin
- Workers are wingless; swarmers (reproductives) have wings and appear in spring
- Smooth, clean tunnels in wood — no sawdust-like frass like termites leave
- Fine, sawdust-like material (frass) pushed out of galleries near entry points
- Most active at night — you may hear faint rustling in walls after dark
Why They're a Problem
Carpenter ants are a serious structural threat. They prefer moist, decaying wood — which is abundant in Northwoods lake homes — but will readily move into sound wood once established. A single satellite colony can expand into multiple nesting sites throughout a structure. Because they're nocturnal and nest inside walls, infestations often go undetected for years. By the time you see swarmers indoors in spring, the colony is likely well-established.
Signs You Have Carpenter Ants
- Large black ants inside the home, especially in spring
- Winged ants (swarmers) emerging from walls, ceilings, or floors
- Small piles of coarse sawdust-like frass near baseboards, window sills, or door frames
- Faint rustling or crinkling sounds inside walls at night
- Soft or hollow-sounding wood when tapped
- Ants trailing along the exterior of the home, especially near wood-to-soil contact
How K2 Treats Carpenter Ants
Carpenter ant treatment requires finding and eliminating both the parent colony (usually outdoors in a stump or log) and any satellite colonies inside the structure. K2 uses a combination of targeted residual treatments, void injections, and exterior perimeter barriers to eliminate active colonies and prevent re-infestation.
- 1Thorough inspection to locate all active nesting sites inside and outside the structure
- 2Void injection treatments into wall voids, sills, and other harborage areas
- 3Exterior perimeter treatment to eliminate foraging workers and block re-entry
- 4Identification and recommendation for removal of moisture sources and decaying wood
- 5Follow-up visit to confirm elimination and address any new activity
Prevention Tips
- Eliminate wood-to-soil contact around the foundation — stack firewood away from the house
- Fix leaks and moisture issues promptly — carpenter ants are drawn to damp wood
- Seal cracks and gaps around windows, doors, utility penetrations, and the roofline
- Remove dead stumps, logs, and decaying wood from the property
- Keep gutters clean and ensure water drains away from the foundation
- Schedule annual preventive treatments — especially important for lake homes
Dealing with Carpenter Ants?
Don't wait — call K2 for a free estimate and fast service anywhere in the Northwoods.
(715) 891-2501Free estimates · Same-week service