Carpenter Ant Inspection

Signs of Carpenter Ants

water dropWet Wood: If woodwork has been damaged by water, it is an ideal location for carpenter ant nests. The carpenter ants do not digest the wood for food (like termites), but make their homes in the weakened wet wood.

carpenter ants presenceCarpenter Ants Presence and Visiblity: Presence of carpenter ant workers that are foraging for food. Just because you see some of these ants inside your home, it doesn't nessarily mean that they are nesting inside.Swarmer carpenter ants will shed their wings and you can see carpenter ants that fly coming out of vents.

ant trailsAnt Trails: As with many ants, carpenter ants form trails that can be seen among window sills, door frames, baseboards, eaves outside, power lines, telephone poles.

frassFrass: These are wood shavings that the carpenter ants kick out of their galleries after they have excavated, dead insects, and waste products from feeding. It looks like sawdust and is found near nest sites.

listeninSounds: Sounds like a rustling in the walls as they move around and build nests


When and Where To Inspect

Because Carpenter Ants forage primarily at night, use a flashlight and conduct inspections in the evening or early morning to locate foraging trails and nest sites. Remember, workers have been known to travel as far as 100 yards from the colony to search for food and water. You may have a long way to go to find the nest of those Ants you found in your kitchen.

common carpenter ant areas A thorough inspection is important to find all the sites. Don't conclude your inspection when one colony is found; several colonies may be present in and around a single structure; both parent colonies and satellite colonies.

Parent colonies contain the egg-laying queen with its broods, as well as the worker ants. The satellite colony has mature larvae and pupae as well as workers. Inspect wooden structures associated with high moisture, where there may be water damage resulting in softened and moist wood. Carpenter ants will inhabit wood structures that has already been damaged by water or insects.

Carpenter ants prefer frames and sills of windows and doors, as well as tub enclosure walls, kitchen and bath plumbing walls, around sinks, chimneys, and in hollow spaces such as wall voids.

Common areas of carpenter ant problems in a house.


carpenter ant sawdust Sawdust debris discarded from the carpenter ants making their galleries

UNL extension publication
Photo: Barbara Ogg, UNL

To locate Carpenter Ant nest sites and trails, focus on these areas:

Outdoors, carpenter ants


  • Moisture problem areas
  • Wall voids
  • Attics (especially under roofing and insulation)
  • Flooring or sub-flooring and along carpet edges
  • Ceilings
  • Windows
  • Skylights
  • Hollow doors
  • Dishwashers
  • Trash compactors
  • Plumbing, pipe chases (kitchen/bath)
  • Pet food locations (both inside and outside) will attract carpenter ants


  • Trees and Stumps (may be nesting in dead or moisture damaged trees or stumps)
  • Along sidewalks and walkways (sidewalks are used a lot by ants to go to and from their food source and nests).
  • Around the foundation (may be below grass covering)
  • Fence lines-Often used by ants to trail
  • Deteriorating landscape timbers or railroad ties
  • Woodpiles and Firewood
  • Leaf litter
  • Debris piles
  • Mulch beds
  • Door kick plates
  • Roof lines and gutters
  • Soffits and vents
  • Windows and door frames
  • Utility entrances (electric, cable, TV, telephone, gas lines)
  • Sheds and doghouses
  • Trash containers


How To Detect Carpenter Ant Galleries

Frequently you can see what looks like sawdust near Carpenter Ant galleries. This sawdust, known as frass, is shredded fragments of wood that have been ejected from the galleries. This is a good indication that a nest is nearby.

If you suspect Carpenter Ants are present but there is no frass, use the handle of a screwdriver to tap along baseboards and other wood surfaces, listening for the hollow sound of damaged wood. If a nest is nearby, often the Carpenter Ants will respond by making a rustling sound within the nest, similar to the sound of crinkling cellophane. Use a screwdriver to probe the wood near a suspicious area; this may reveal excavated galleries.

carpenter ant damage

Notice how smooth the galleries appear.

carpenter ant damage Carpenter Ants clean and polish their nests and push out debris (shavings, frass) through holes.

Use a screwdriver to probe the wood near a suspicious area; this may reveal excavated galleries.