Carpenter Ants are large black ants that you notice most times climbing up and down tree trunks or scurrying on the pavement. There are times when these pests enter the home and they become public enemy number one fast. Don't be alarmed if you are noticing these ants here and there in the house because they will hunt for food and often times your house is like a McDonald's to them. Seeing a few ants or even a few ants daily doesn't mean you are infested. An inside perimeter spray will keep them at bay. So what are the signs of a real infestation in the house? You need to ask yourself these questions. Have a recently or in the past year had any leaks in the house? Then you need to ask your self if you've seen these ants in large numbers in the night time hours?
These ants are most active in the evening hours after 9PM and they are very attracted to damp or water damaged wood. It is easier for them to excavate a gallery for them to live in. Next thing you want to do is search for areas where there is saw dust or "frass" showing up. Maybe you notice every day "saw dust" is falling from a particular window sill area even after it's been vacuumed. This could be where the buggers are nesting. It is important to locate the nest to eliminate it. Another way to see where they are nesting is if you come across them foraging at night try to get them to take some sugar or another kind of crumb by placing it in there direct view. If they pick it up you will need to follow the ant and most likely he will disappear into the area he is nesting.
When the nest has been determined you will need to drill a few holes in the void they are nesting and "dust" the void with an insecticide dust. Baiting for these ants rarely work although recently over the past few years there has been success with a Maxforce carpenter ant gel and some advance carpenter ant granules that work. If the ants remain elusive then baiting might need to be your best way. There is a new formulation of chemicals that are working well with ants too. They are under the trade names Phantom and Termidor. The ants pass over the chemical and unknowingly track it back to the nest and infect the nest, killing it off.
Ways to help in keeping the ants away from your home would be to trim back any tree limbs that are touching your house or the roof, be sure that any cables or pipes that enter your house have no opening around them and if they do them caulk them, also cut back any bushes that are growing close to your home and make sure they are not touching the house. Call a pest control professional to "power spray" the perimeter of the home placing down a chemical barrier. This will also help.