Wil- Kil's Pest of the Month: Carpenter Ants - A Structural Damaging Pest

Here in Wisconsin, the carpenter ant is the most destructive and economically important pest affecting homes and businesses. At Wil-Kil Pest Control carpenter ants are among the top 5 most frequently treated pest.

Identification: Carpenter ants are medium to large, all black or black-and-red ants. The workers range from ¼ to ½ inch long and the queen can be up to 1 inch long. Carpenter ants can be distinguished from other ants by having a rounded thorax (middle body region) and only one segment that connects the thorax to the abdomen. You can see this by taking a close look at the ant.  

Damage: Carpenter ants excavate small tunnels and galleries in soft wood or foam insulation. The tunnels are smooth, clean cavities, and turn the wood to a soft texture. Most of the time the ant damage is minor compared to the damage caused by moisture. Remember, carpenter ants do not eat wood; they nest in already weakened or softened wood.

Control:The best way to control carpenter ants is to locate the nest. By simply killing the workers that are out foraging you will have minimal long-term success. You need to find and kill the queen to have lasting success.

A big question we receive is whether or not you have a carpenter ant nest inside your home. If you see any of the following, you may have a nest in your home:

1. Carpenter ants inside between November and March

2. Large numbers of winged ants inside (called swarmers)

3. Sawdust (called frass) falling from ceilings, cabinets, or other wood structures

4. Consistent indoor sightings of at least 15 per day

Outdoors carpenter ants often nest in trees with decaying wood, rotting fence posts, stumps, old firewood, dead portions of standing trees, and under stones or fallen logs. The outdoor colony can be treated with a liquid or dust pesticide directly into the nest. Baits or gels can also provide excellent control if you cannot get to the nest site. Always read and follow label directions.

Prevention:

-Overhanging tree branches should be cut back to prevent them from contacting the structure and providing an easy access route for ants

-Check where electrical and water lines enter the structure and seal any gaps

-Stumps, logs, and woodpiles should be eliminated or moved as far away from structures as practical

-Store firewood as far away from buildings as possible and if possible elevate to allow air circulation

-Correct moisture problems such as slow leaky pipes

-Clean out clogged gutters

-Make sure doors, windows, chimneys, and skylights are properly sealed

-Replace any moisture-damaged wood

If you suspect your home or business has carpenter ants, please contact Wil-Kil Pest Control, based in Menomonee Falls, at www.wil-kil.com and a specialist will be happy to assist you.