Wood Infesting Insects: Carpenter Ants
by
Steve Sproul
General Contractor
#450095
Carpenter ants are found throughout the U.S. but are generally more of a problem in the Pacific Northwest, Midwest and Northeast. Most are medium to large black or red and black ants that are seen on sidewalks or in the home.Workers range from 1/8 in. to 1/2 in. long (that is a big ant) and queens are just under an inch. All carpenter ants have a constricted waist and elbowed antennae. Carpenter ants have only one segment or node on their waist. Unlike regular ants that do not nest in wood they are darker in color. They nest in the ground, in dead trees, in firewood and sometimes if conditions are right, in the home. They especially like weak or water damaged wood. Unlike termites or powderpost beetles, they do not eat wood. Carpenter ants feed on protein sources, such as other insects, or on sweets. Often they can be heard chewing on wood, or they will expel
coarse sawdust and debris from the nest. There are often small fragments of insects, foam and other debris mixed in. When nesting in wood, carpenter ants construct irregular galleries that run with the grain of the wood. They remove wood with their mouths and kick it out. Unlike termites, carpenter ants keep their galleries very clean and smooth. Over time most of the softer wood will be removed, and the wood will look a bit like a Swiss cheese. They will only weaken the wood to its breaking point. In many situations they can be seen as beneficial because they can indicate moisture problems in the home, and this moisture poses a far more serious structural threat than the ants themselves.
During the first three to five years a colony will grow from a single queen to about two to three thousand individuals. Once a colony reaches this size it develops winged males and females (kings and queens) for the first time. Outdoors during the spring, and indoors at any time of year, from twenty to four hundred winged individuals will emerge from the nest and swarm. The swarm tells you that the colony is at least three years old, and if found indoors or seen during winter, means the ants are nesting inside.
Worker Carpenter ants will forage up to fifty yards looking for food. Once a food source is located the worker will communicate to the nest and recruit other workers to help bring the food to the nest. Carpenter ants diet includes sweets, plant juices, honeydew (a sugar secreted from aphids), other insects, honey, meat scraps, grease, fats and even pet food. Carpenter ants have been known to grow fungus in galleries and to farm aphids for food.
Control and treatment-The best long-term solution to Carpenter ant problems is to find and treat the nest. Once the queen has been killed, the colony has no chance of surviving. The initial step in locating the colony is to do a little detective work. Ask yourself where the ants have been seen? How many ants per day have been seen? Are the ants associated with food? Are any ants seen in the winter months? Is any firewood stored indoors (in an attached garage)? Have I ever had any water problems in the house? Have I seen any swarms, and if so, where where they? If more than five to ten ants are seen in the house every day or large ants are found active during the winter, then carpenter ants are probably nesting indoors. Spraying every baseboard inside the home may seem to get results because the ants are repelled by many insecticide sprays, but unless the nest is contacted by the treatment, the ants will reappear. If you think you know where the nest is, spot treat that site once with any registered ant or roach-killing insecticide and see what happens. Spectracide, Dursban, Sevin, and Baygon can be bought at most hardware or garden stores. Placement in the nest is more important than what you use.
If small numbers of ants start to appear as the air warms up in the spring, but the ground is still cold, the nest is most likely along an outside wall. Carpenter ants, like all insects, are cold-blooded, and if the temperature drops below 50F they cannot move. During indoor inspections your best bet is to look for a moisture problem. Carpenter ants do best when the moisture level is above 15%. Wood affected by water seepage from clogged gutters, leaky roofing, condensation problems, contact with soil, poor ventilation or weather is prime nesting territory. Check for nest sites in areas with small voids, such as seldom used hollow core doors, delaminating plywood, or in large wooden beams that may have preexisting voids.
Outdoor nesting ants are most troublesome in the spring. Old tree stumps, firewood piles or trees with dead branches or heart rot may be the main nesting site. Carpenter ants will also nest in lawns or bare soil. Look for sawdust, pies of shredded wood, or piles of soil mounded outside the nest. As indoors, treat the nest directly to eradicate it.
For small numbers of ants filtering into the house from outdoors, finding the nest may not be practical. Spraying a two to ten foot swath around the outside of the house during spring and summer will usually discourage Carpenter ants from coming inside. Treat ground nests with dusts or granules. Keep garbage cans clean, wash food scraps from dishes and do not leave pet food sitting out for extended periods. The little ant baits sold in grocery stores are not very effective in keeping Carpenter ants out of the home. They either are not attracted to the bait, die on the way to the nest, or learn to ignore the bait.
Do you need to call in professional help? It depends on how much you hate the ants. Some people just do not like sharing their breakfast table with insects. Some pest control companies will drill between each stud, door sill and window frame, inject pesticide and patch and paint the holes. This is labor-intensive and expensive operation and uses a large amount of pesticide. Although this is an effective approach, it is like shooting a rabbit with an M-1 tank. Spot treating the nest directly is just as effective.
For Carpenter Ant Repair Contact:
Steve Sproul General Contractor
CA lic.#450095
2775 Prosser Rd
Sebastopol, CA 95472
Phone: 707-953-1708
e-mail:stevesproul@comcast.net