Here in western Washington, carpenter ants are an annual right of spring. After a long winter’s nap, they are starting to move around, and many homeowners are already discovering these invaders.
Carpenter ants don’t eat wood; they only damage it in the process of building a nest.
They feed primarily on aphids and scale bugs, milking them for honeydew, and these insects play a significant role in explaining carpenter ant behavior.
Because insects like aphids feed on sap, they are slaves to the plants they feed upon, and the plants, in turn, are slaves to the seasons.
So, it goes something like this: plants move their sap into their roots for the winter. Plant parasites can’t get the sap, so they lay eggs or go dormant; they aren’t producing honeydew, so the ants go dormant. The ants take a nap for the winter and most of the spring.
As spring approaches, plants move their sap out of their roots, the plant parasites return and start producing honeydew, and the carpenter ants wake up to tend their flocks.
Aphids and scale bugs are to carpenter ants what cows are to us, and the ants will not only milk them but defend them from predators and move them from one plant to another.
In nature, many insects have built-in alarm clocks, and carpenter ants are no exception, but when they nest in a heated structure, they can get thrown off kilter. If you see carpenter ants inside your home before May, it is usually because of a nest in the building. These ants are often half asleep, wandering around for water and sweets. If you do nothing, you will stop seeing them indoors as they find sap-feeding insects and establish feeding trails outdoors. Their disappearance doesn’t mean they are gone; they are just foraging outside. If left untreated, the colony will continue expanding in the building and can do significant damage.
This time of year, aside from ants inside, you should be on the lookout for ants standing around on the foundation or decks. You can often detect Carpenter ants crawling up the corners of the foundation. Carpenter ants will avoid hiking over rough terrain and make trails along sidewalks, decks, landscape edging, and garden hoses. Utility lines coming to your home can also provide a pathway for them, especially if they pass through tree branches.
If you find these ants in your home between November and May, it is a clear indicator that there is a nest in the structure. You need to take prompt action to avoid damage.
Even though many products are available over the counter for carpenter ant control, treatment for active infestations should be performed by trained, experienced people. The most effective materials are unavailable to the general public, and no one has figured out how to put expertise in a can.
