Carpenter ants can weaken the structure of wood given enough time, according to the University of Minnesota Extension. The level of damage gradually increases and depends on how long a colony has been present.
While termite damage is often more serious, carpenter ant damage can also be severe if nest growth proceeds unchecked for a few years, explains pest control company Orkin. Population expansion means more carpenter ants tunneling through wood and further weakening structures. Wood shavings under wooden objects may be evidence of a serious carpenter ant invasion. People may also be able to hear slight, rustling noises in walls or in woodwork. Winged ants appearing from ceilings, walls and other places practically guarantees an infestation is present.
If a carpenter ant invasion is suspected, Roger Harris for About.com recommends checking for wood dust and shavings in bathrooms, kitchens and other potential sites of water leaks. A stethoscope or empty glass pressed against evergreens or hollow tree stumps close to a house can also turn up noise indicative of a carpenter ant invasion.
The University of Minnesota Extension recommends keeping wood higher up to allow better air circulation and keeping firewood as far from a house as possible. Trim branches that touch a house and remove tree stumps. Throw out wood damaged by moisture.