Evidence of Carpenter Ants Presence and Infestation

If ants are coming in, there may be a nest outside the house and eventually they may establish satellite colonies in some part of the structure. Be certain they are carpenter ants and not moisture ants, termites or yellowjackets.

• Presence of ants (workers or winged reproductives): An occasional ant may be a scout looking for food and may not indicate the presence of a nest, but continuous or numerous ants are a sign of nesting.
• Sawdust: Accumulating in piles or caught in spider webbing; has a finely-shredded appearance. Do not confuse with small sawdust from construction
• Trails
• Sounds: Rustling or tapping noises produced when disturbed ants rasp the substrate with their mandibles or gasters or when excavating wood.

Coarse sawdust is a sure sign, but it is often difficult to find the nest. At night, turning on a light to observe ant activity around a sweet that has been left out may reveal an "ant line" to and from the nest. Sometimes the insects' activity can be heard in walls. Tapping areas suspected of harboring nests may produce a hollow sound, and some excited ants may appear.

Dr. Hansen's research showed that some common elements accompanied infestations. Although other types of structures were attacked, most infestations were in houses with these characteristics:

• Wood frame
• Crawl space
• Cedar or plywood siding
• Moderately to gently sloping roof
• 5-25 years of age
• Vegetation (trees and shrubs) surrounding the house
• "Structures located near the edge of the forest were more liable to attack than those located further away." This is because the ants which have well-established nests in trees or stumps can easily move to the nearby house and establish satellite colonies.

Ants move along definite trails by following a chemical scent or visual clues. These trails can be above ground or subterranean and are actually constructed by cutting away vegetation, removing pebbles, excavating soil and even by covering open trails with a roof of needles from nearby trees. Trails can vary in width from 1/8" to 3/8".The ants from a colony will follow the same path each year even if grass has grown in it. They will clear the old trail.

Again ants prefer natural, easy and protected routes:

• Edges of cabinets, furniture
• Excavated trails through insulation in wall voids
• Along wiring or plumbing which cuts through studs
• Wires or branches coming to the house
• Root channels from infested trees or stumps which go beneath the house.

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