Easy DIY method for getting rid of a carpenter ant infection inside the home without the use of chemicals or other toxic substances.
We’ve had two major infestations of carpenter ants to deal with during the 25+ years of living in our home.
The first occurred shortly after we moved in. Our house was built in 1951 and sits in a semi-rural neighborhood with lots of trees, vegetation, and moisture due to a backyard lake. Needless to say, it is the perfect environment for critters of all kinds including carpenter ants.
The first infestation had me calling the pest control company in a hurry!
Calling Pest Control for Carpenter Ants?
Carpenter ants are huge and very scary looking as you can see from the picture above. While they do sometimes bite, there isn’t any poison, so if you are careful, you can pick them up with your fingers and throw them in the toilet or flush down the drain with no problem.
At the time, though, I didn’t know any of this, so seeing dozens of large ants running around my then retro style 1970’s orange and yellow kitchen was not a pretty sight.
I picked up the phone and called pest control and after a couple of toxic sprayings around our house, yard, and then in our attic over the course of a week or two, the carpenter ants were gone.
The Natural Approach is Very Effective
Our second infestation of carpenter ants happened just a few weeks ago, and this time, I handled it very differently.
Having the knowledge and wisdom of 20 years of green living behind me, I was determined and very confident I could resolve this infestation with zero pesticides and no call to pest control.
My youngest was especially freaked out by the enormous size of the carpenter ants even after I explained that they don’t have a sting like other types of ants and picked up one in my fingers to show her. Unfortunately, my little pep talk and demonstration didn’t do much to alleviate her fears of these intimidating, wriggling creatures.
The carpenter ants were swarming in our kitchen and bathrooms and after starting with just one or two here and there, over the course of a week, they came in by the dozens overnight while we slept making for a very scary turning on of the lights in the morning if you know what I mean. We spent the first 15 minutes of the morning vacuuming them up before we could even get started with breakfast!
Find Where The Ants are Trailing
After watching and observing their patterns over the course of a day or two, I determined that their primary mode of entrance into our home appeared to be the drain of the dishwasher.
Knowing where the carpenter ants are getting into the house is a helpful piece of information, but not entirely necessary if you wish to eradicate them yourself via nontoxic measures.
In our case, the dishwasher drain seemed a likely ground zero, so I mixed up my carpenter ant killer ambrosia and set the bait.
How to Mix Nontoxic Bait
My one cup of ant bait consisted of the following all of which cost less than $1. Believe it or not, this is all that was needed to get rid of ants quickly and easily.
- 1/3 cup of powdered white sugar
- 2/3 cup boric acid (where to find)
That’s it!
Note: you may use borax powder for a less strong mixture.
When I took our container of boric acid out of the garage utility cabinet, it consisted of a bunch of hardened chunks that needed to be pounded out as I hadn’t used it in a long time.  So, I took out my mortar and pestle and pounded out a few big chunks to re-powderize and then measured it into a small ziplock bag that contained the appropriate amount of powdered sugar.
Boric acid is a colorless white powder that is a mild antiseptic, but certainly not a problem to the health of your family even if you touch it with ungloved hands. It is found in nature in some volcanic environments near Tuscany and Nevada.  Boric acid and its salts are found in seawater and plants including almost all fruits.
Keep Away from Pets and Children
Of course, you need to keep it away from small children and pets. It is poisonous if ingested or inhaled in large quantities.
However, it is probably the least toxic form of insect bait you can use around your home. The one exception is diatomaceous earth, which unfortunately doesn’t work as well or as quickly for large ants where I live.
Where to Place the Bait
I placed a couple of tablespoons of the carpenter ant bait in the lid of an empty jar I was going to recycle and placed inside the dishwasher on the bottom near the drain just before going to bed.  Before I did this, however, I was careful to run a load of dishes and empty everything out so the dishwasher was completely void of any plates, glasses, or utensils.
A Happy Ending to our Carpenter Ant Infestation
The next morning we were delighted to see that there were no carpenter ants running around the kitchen! Â When I opened the dishwasher to have a peek, they were swarming around the bait but were totally confined to that area.
I gently closed the door of the dishwasher and left the ants there, happily eating away at the bait they would take back to their nest to kill the whole colony.
It took a few days, but gradually, the carpenter ants swarming inside the dishwasher completely disappeared with nary a stray one left!
When I needed to run the dishwasher in the interim, I simply removed the container of bait, ran a load, emptied the clean dishes, and then replaced the bait near the dishwasher drain.
Simple, effective, non-toxic, and best of all, cheap with no call to pest control to come and spray who-knows-what hormone-disrupting, carcinogenic chemicals around your home for your family to breath and absorb!
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John C.
I tried this but it didn’t work at all. In fact, I was able to see the carpenter ants walking carefully around the stuff in order to avoid it.
Casey Battles
This sounds all good and well, except for the fact that we found over 500 dead carpenter ants in our basement after bate and spraying from a pest control company last year and are now seeing flying (mating) carpenter ants this Spring, meaning that it did not get rid of them.
Brandon
Do you think it’s ok to do this if I have a cat
Sarah
We have two indoor/outdoor cats and we use it. Our cats don’t bother with it.
Bernice
Would bees be attracted to this mixture? Would it kill them? I have carpenter ants at the base of a maple tree – eating the dead wood and I would like to get rid of them without harm to other insects.
Sarah
I don’t know. I’ve always used it indoors.
Ryan
An alternative to Boric Acid that I’ve found very effective for ant control is a Baking Soda/powdered sugar mix.
Amanda
This morning I woke up and there was a giant ant in my bathroom followed by a bunch of them the rest of the morning. I found more in the sunroom which is on the other side of that wall so I have been squishing them and vacuuming them up all morning. I found your article on them and sent my husband out for boric acid. When he gets home from work we will be trying. I really hope it works so I don’t have to call the exterminator. Thank you for the idea.
Hannah
How do I not worry about carpenter ants. I can barely sleep
Hannah
Hi, I’m very scared about my house and it was an old house and we tared most of it apart when we bought it and rebuilt it and I can already see Carpenter ants that were not seen when were rebuilding our house like two years ago. Could moisture already been in our house? And how long does it take til you see some kind of damage? I’m really worried!
Thanks
John Larkin
How do you suggest to use the mixture if they are coming in through holes in the ceiling with little to no attic access. Thanks
Irene Kafon
Hi I have a pet and I don t feel confident in using this particular treatment Any others that wil be safe for my pet?
Thank-you
Sarah
I’ve used it with both dogs and cats in the house. I do not have another option to suggest.