Carpenter ants are very beneficial in nature as they can be an important factor in the decay process of rotting trees and stumps. However they are a serious pest when they invade our homes. Carpenter ants do not “eat” wood. They cannot digest cellulose. The damage they cause is a result of tunneling as they form their nests.
HOW CAN I PREVENT INFESTATION?
Eliminating moisture is the single most effective method of discouraging carpenter ants.
- Ensure there are no water leaks that result in damp wood;
- Cover wood that is stored outside to keep it dry, and elevate it off the ground if possible to allow air circulation;
Reduce opportunities for carpenter ants to enter the building.
- Remove any carpenter ant nest on the property;
- Store wood far away from buildings;
- Remove tree stumps and roots to discourage ants from nesting as the stump decomposes;
- Trim branches that overhang the home, and trim any branches that touch any telephone, cable or power lines that are connected to the house;
- Plant shrubs so they do not come in contact with the home.
HOW DO I IDENTIFY CARPENTER ANTS?
Carpenter ants generally look like all other ants, except they are
larger. They are easy to distinguish from termites by looking at body shape.
- Body Shape – narrow waist (the much less common termite has a broad waist;
- Color – usually black or reddish brown, sometimes both;
- Size – length slightly less than 1 cm to over 2 cm ;
- Legs – 6
- Wings (when present) – 4 wings (front wings are (front longer than rear wings)
- Antennae – bent
HOW DO I KNOW IF I HAVE CARPENTER ANTS IN MY HOME?
Live Ants – you may see carpenter ants inside your home. They could be simply foraging for food, or they have a nest inside. Regardless, there is a nest somewhere nearby, and you will want to eliminate it. Look for ants outside at night (use a flashlight with a red cellophane filter). Check around the foundation, porches, shrubs and so on. Winged ants inside the house in early spring are a good indicator that a nest is nearby.
- Debris – look for small piles of sawdust and piles that may contain small insect parts and pupal cases. Check corners, window sills, under insulation and anywhere you think they might be travelling.
- Noise – It is often possible to hear a crinkling sound inside the walls if a nest is present. Tap the wall and listen using a stethoscope or drinking glass held up to the wall.
WHAT SHOULD I DO IF I FIND CARPENTER ANTS?
With effort and patience, it is possible for a homeowner to effectively and safely deal with a carpenter ant problem.
- If you can find the nest, remove it by cutting out the wood in which it is located. If this is not practical, the nest can be destroyed using a variety of insecticidal dusts designed for this purpose.
- If you do not have direct access to the nest, toxic bait placed along ant trails will eventually be tracked back to the nest and destroy it. It may take up to a week or more to be fully effective. Sprays that kill ants on contract are not effective in eliminating nests.
If you think you are infested, the following websites may be helpful.
Identifying Carpenter Ants
Killing Carpenter Ants
Government of BC Insect Pests – also aphids and yellow jackets
Healthy Canadians Government of Canada – carpenter ants and many other pests