Fixit: Let a pro take on carpenter ants

Q We have big black ants in the kitchen. What are they, and how do we get rid of them?

A It sounds as if you have carpenter ants.

An occasional carpenter ant in your home may be a scout that made its way indoors to snoop around. But if you see more than a few, they probably have made a nest inside.

You don't want that. Carpenter ants can destroy a home's wood structure. These ants are part of nature's cleanup crew, helping to rid the world of decaying wood, dead insects and other debris. But they need to be conducting business outdoors -- in old logs and trees -- not in your house.

Because carpenter ants like damp wood and areas that are or have been wet, check likely nest areas:

• Look carefully in and around the sink and dishwasher. A slow plumbing leak may be dampening areas behind walls and floors.

• Check walls and ceilings for evidence of leakage from a faulty roof, gutters or even winter leakage due to ice dams or attic frosting that occurs after cold and snowy winters.

• Check the flashing (material that sheds rainwater) around chimneys, skylights, windows or doors; an improper fit can create damp spots.

Finding and destroying nests -- indoors and out -- is the way to end the infestation. You also must solve the moisture problem and replace any damaged wood to prevent re-infestation.

The Minnesota Extension Service suggests that homeowners use baits listed for use on carpenter ants. Those that use boric acid as an active ingredient may be slow-acting, but they can be effective.

Because finding and treating nests can be difficult, hiring a pest-control company to do the job may be your best choice. Such companies also have access to chemicals not available to consumers. Look for a company that will find and treat the main nest outdoors as well as any satellite nests indoors. Once a property is effectively treated, a regular spraying schedule for carpenter ants is unnecessary. You just need to keep the house dry and well maintained.