Like most household pests, Carpenter Ants are a topic that homeowners want to know more about. What are they? How can you tell they are in my home? What are the risks? Are they dangerous to my home or family. Here are the answers to all of those questions, and more, answered by a experience home inspector of 25 years.
Q: How serious is the damage caused by carpenter ants?
A: Some pest companies have seen new homes, homes under construction and older homes where the carpenter ants have caused damage in main structural beams and wall studs. It is more common; however, for carpenter ants to do almost no damage. Unfortunately the pest industry has set a standard in lending that if carpenter ants are found in a house they must be treated. Even though the damage or debris (frass) is often not visible unless wall or ceiling cavities are opened. Infestations/nests are often discovered during renovations or changes in usage.
A good inspection will locate the commonly large piles of wood shavings that carpenter ants leave, hence the name. I, in the thousands of inspections I have completed on homes, apartments, and commercial buildings have been able to tell the customer/contractor where the damage was (if any). The carpenter ants are as lazy as the rest of us & don't move the wood pile very far.
Q: How do you get rid of them?
A: Killing the visible ants foraging around a home is merely removing the symptoms. However, if you live in their house on a wooded lot or your neighbors don't mind the carpenter ants coming by for a "drink & sandwich" it is going to be impossible to kill them all. So be cautious of the pest company that says the nests must be located and destroyed. Most treatments are just setting up a perimeter & if they can catch the satellite colony in the house they can kill it.
Remember the carpenter ants are the top of the ants chain & they are not stupid. They know that Sally Ant did not come back & Fred Ant is not the same after going to eat at that house. I have seen them walk on the bottom side of a board, wire, or stick to cross a perimeter spray job. Do some perimeter spraying yourself, if you are knowledgeable enough to, in the Spring & Fall & maybe set an insect bomb off in the attic or under the house at the access (do not enter the crawlspace to apply any chemicals). If this does not keep your family happy, then call a professional pest company. Let them drill the holes, crawl under the house & in the attic & treat it.
Q: How do you find the nests?
A: Through years of experience & training home inspectors & pest control professionals have gained a sense of where the nests are likely to be. Even with a thorough inspection for evidence and tracking ants, they are generally not able to locate the main nest as it is not generally in your house. The occupants observations are the most important. Carpenter ants may not move out of the nest for days in some weather conditions. That is one of the reasons we call for treatments so often in a real estate transaction.
Q: Are the pesticides used, toxic to people in the home?
A: Yes, pesticides can be like medicine maybe. When used properly they are safe and effective. So be cautious when they say; "We do not place pesticides where humans or animals will come in contact with them or We always practice integrated pest management." Which means use all methods possible to control pests with minimum use of pesticides. I have always been amused by where my kids & pets can go. When pesticides are not used properly they can cause health hazards.
Q: How do the small tin ant traps work?
A: They don't. They are not traps. They contain a small amount of ant poison that is not effective for carpenter ants. However, if you call a good home inspector, with your help the inspector can likely find the leak or conducive conditions that make your home attractive to carpenter ants. If you remedy the problem, then you may not need to spray for ants in the future.
Q: What about the little bottles of ant poison? Do they eat it and take it back to kill the queen and others in the nest?
A: Remember the carpenter ant is not stupid. Dr. Laurel Hanson has been working on a bait for a number of years & we are just starting to see it used. Any poison must have a good residual to have effect when it is transferred to other ants. Baits have been effective for some ants & termites. We will have to see with carpenter ants.