Recently, I noticed an increase in the number of large black ants on the deck attached to the back of my house. Until my father mentioned it I did not really give it a thought but when he pointed out that these were carpenter ants I began to get a bit concerned. The fact that some of them were working their way under the siding indicated that I should probably do something about this before it became a major issue.
Previously, I had used some commercial sprays and/or granules to control small (probably sweet or grease eating ants) colonies next to my driveway but this problem appeared to be more widespread. Checking in at the local DIY home repair superstore, I found there were a number of different options for treating this problem. What I failed to do is to consider how/when to apply my chosen solution. Note: Before applying any pesticide make sure to thoroughly read all of the instructions and warnings. It is also a good idea to discuss this with a professional or somebody who has gone through the process previously.
Choosing a concentrated liquid pesticide I applied it to my deck, foundation and portions of the siding with a garden sprayer in the areas where the ants were seen. So far, so good. However, around an hour later I ran into an unforeseen consequence of NOT getting some advice first - mainly that the ants that were disturbed and/or dying had to go someplace. Around an hour later I started to notice a tremendous number of dying ants inside my house adjacent to the treated area. Since this seemed to indicate that I might already have an ant problem in my house and not just on the deck I decided it was time to call the professionals for an analysis.
Getting some suggestions from co-workers and neighbors, I contacted a local company to have an analysis done - some of the larger franchise operations can be very expensive but the company I selected provided a free estimate and their treatment options were reasonably priced. Upon being told of the problem and what steps had been taken, they suggested a localized treatment instead of a full home treatment - a considerably less expensive option. They pointed out the likely problem area, where there seems to have been moisture damage in the past, and explained how the treatment should kill any ants my spraying had not as well as providing a residual knock down for any unhatched ants that came along later. They informed us that the treatment would take 7 to 10 days during which period I would still see a few ants but to let them know if the problem persisted.
The professional was very willing to share some suggestions on what to look for and what preventitive steps to take to help prevent this from occurring again. Here are the suggestions I have gotten from the professionals as well as those that friends and neighbors have gotten from them as well.
Border/Area Treatments - If you live in an area with a lot of old trees, there are probably carpenter ants in the area. Keeping them out of your house is the best solution. There are many granular and liquid treatments. Apply them from the house outward (you want to keep them out, not push them closer to your home!). If you are using an area treatment as more than a border guard, make sure that you start near the home and work outward.
Look for Ants - The most obvious sign of a problem is ants - if you see many of them in a small area, you might have a problem. You may always have a few isolated ants around, but if you are finding a couple every day in a specific area you may have a problem.
Check the Interior - Carpenter ants often gain access in areas where water damage has softened up the wood for them to work with. Look for discolored areas where you have have had water (where it should not be) in the past. Also check for signs of ant activity. The most obvious sign is small areas where there appears to be sawdust (a result of the ants boring through wood). Also look for any areas that might indicate access to the outside - in my case, there are areas where (once the insulation is moved) you can see daylight between the foundation and the frame of the house.
Seal it up - Caulk, putty, or otherwise seal up any openings you found. Caulking seams is a fairly quick and easy process. If you see areas where there was water damage, you will want to address whatever may have caused the damage (if water can get in, ants probably an also!)
When in doubt, call a Professional - Many local companies will provide free analysis and estimates. If you are unsure you have a problem, contact them. The sign of a good DIY home handyman is knowing when to call for backup.