Carpenter Ant

I am often asked, what’s the latest on controlling Argentine ants? Fire ants? Carpenter ants? Well, if my 20+ years experience in this industry have shown me anything, it’s the more things change, the more they stay the same.

The truth is, the "strategies" used to control ants pretty much stay the same. You can (1) treat the areas where the ants are seen, treat the foundation outside and then pray; (2) find the colony and treat it directly and pray you found all the colonies; (3) you can employ ant baits and pray the ants eat enough of the bait to eliminate the infestation; or, (4) you can use one or more of the first three strategies in various combinations and then pray what you did worked.

The common denominator in all these strategies is prayer. Once we leave any property, chances are we will be asked to return to provide additional service. Ants are just plain difficult to control no matter how hard we try, species, such as Argentine ants, crazy ants and ghost ants. Sure, you’ll regularly encounter situations where you get the ants the first time, but those experiences are typically the exception not the rule.

No one single method works ideally for every situation involving any ant. Experience is a critical factor in success, and carpenter ant control is no exception.

The basic process one uses to control carpenter ants is the same as that used for any pest::

1. Identify that carpenter ants are involved;

2. Find the colonies where the ants are living;

3. Direct the appropriate control measures (non-chemical and/or chemical) at the colony locations;

4. Correct any contributing conditions; and,

5. Follow-up to ensure what you did worked to the customer’s satisfaction.

WHAT'S NEW? The good news is that in recent years, new products are being introduced specifically for carpenter ants. Several bait products have appeared that can be successfully used for many carpenter ant infestations. This past year, the Clorox Company introduced Maxforce Carpenter Ant Bait Gel, and two years ago, Whitmire Micro-Gen introduced Advance Granular Carpenter Ant Bait. Last year also ushered in the age of liquid ant baits with Waterbury’s Drax Liquidator Station and Eaton’s Dr. Moss’ Liquid Ant & Roach Bait. This year, Whitmire Micro-Gen introduces the A.C.E. Station, a refillable exterior station that contains liquid ant bait. Clorox is also introducing an exterior, refillable ant bait station that will hold different types of ant bait, including a liquid bait.

Why all the interest by manufacturers in offering liquid and gel ant baits? If you remember your basic ant biology, worker ants are unable to consume solid foods. When you apply a granular ant bait, the workers must carry it back to the colony and feed it to the larvae. The larvae then regurgitate digested bait to the workers who feed it to other larvae, the queen(s) and other workers. When a worker encounters a liquid food it likes, however, it readily ingests large quantities that it then carries back to the colony to share with its nestmates. Workers, larvae and, hopefully, queens are all immediately introduced to the bait. The more workers that are recruited to, and feed on, a liquid ant bait, theoretically, the faster the results that should be seen.

We know that most every pest ant species depends heavily on the sweet honeydew produced by homopterous insects, including aphids, mealybugs and scales. Take the time to observe carpenter ants in the evening on aphid-infested trees and plants. Note all the activity surrounding these "ant cows." It stands to reason that given the right bait matrix and delivery system, liquid ant baits should prove to be a powerful tool in controlling carpenter ants, especially for those situations where the colony is out of reach (e.g., high in a tree or on a neighboring property).

So, carpenters ants will now go the way of fleas and German cockroaches as a thorn in our side, right? Not so fast. Liquid baits are a tool that should prove successful, but let’s get them in the field and try them for a few years. Some pest management professionals have noted that carpenter ants are not so cooperative when interacting with ant baits. Researchers at Purdue University, for example, have observed carpenter ants readily picking up granular carpenter ant baits only to deposit them or bury them along side the trail a few minutes later. Likewise, granular baits have been taken into the colony then kicked back out later. Will we see similar occurrences with liquid baits? Probably. The difficult factor with liquid baits, based on early observations, is the reluctance of carpenter ants, in some situations, to recruit large numbers of nestmates to liquid bait stations. In one case, the interaction of ants with the stations is tremendous — in others, the ants bypass the station. Maybe someday we will understand why.

Such observations, however, do not mean that granular baits are not effective — they do work in many situations — it just means that some carpenter ant colonies are finicky about their food. It is up to you — and your considerably larger brain — to "outthink" the ants’ built-in survival mechanisms by maintaining persistence in changing baits or control strategies to effect the results desired by your customer.

It is highly recommended you try these new products in a variety of situations and against a variety of different carpenter ant species. Make a point of recording your experiences and observations and then conveying them back to the manufacturer of the product(s) you use. This information will prove invaluable toward improvements of the baits and the delivery systems.

WHAT STAYS THE SAME? The best strategy for carpenter ants is still to find the main colony and as many satellite colonies as possible and treat each directly. Finding the main colony is still the critical factor in long-term relief. It will be associated with a constant source of moisture and so is most likely to be found outside. Satellite colonies can appear almost anywhere inside the structure, even inside appliances.

A nighttime inspection beginning about one hour after dusk is still the best — although impractical — time to inspect for carpenter ants. Offer foraging ants pieces of freshly killed insects (e.g., crickets) or liquid ant bait, then follow the trails back to nest locations. Confirm wall void infestations with a stethoscope. Drill into and treat appropriately any colony found. Carpenter ant researcher Dr. Laurel Hansen strongly recommends removing all electric outlet plates inside and dusting the wall voids behind them. The reason this seems to work so well is the propensity for carpenter ants to use electric wires as highways through a home. If the home has brick veneer, it may be necessary to drill and dust behind the veneer. The space between the brick and the outer wall of the house is often used by ants and other pests as a harborage. Use your best judgment based on what you see at the house.

Establish bait placements (granular, gel and/or liquid) along each ant trail discovered. Return in a day or two to ensure the bait is being consumed by the carpenter ants. If so, give the ants more of what they like. If not, try another bait. If the ants fail to accept any bait offered, the only hope is that you have found and treated the main colony.

Provide the customer a list a recommendations for minimizing ant infestations, such as moving firewood piles, trimming back tree branches and sealing exterior cracks. Completing these tasks is crucial for long-term relief. A progressive company might even offer completing such tasks as part of the service (for an extra fee, of course).

SUMMARY. No magic bullets are on the horizon for carpenter ants although liquid bait stations outside, maintained year-round, may offer some semblance of long-term reduction of ant activity around a given structure. Hard work, good investigative skills and persistence are still the keys to bettering this bothersome pest.