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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After using lids of mason jars and mixing the ingredients together in a glass bowl can I run these thru the dishwasher and it will be safe to use with food?
Second question: does it have to be powder sugar or can I use granulated?
I would recommend handwashing.
Yes, I’ve had the same experience with ants. The bait works wonders. I’ve used it on carpenter ants in the house twice and they were eradicated within 2-3 days, and on the tiny sugar/odor ants many times to see them eradicated within the first day. Really.
Terro Liquid – this is what you want if you don’t want to try making your own. It is perfectly formulated and very cheap, a few dollars at hardware or grocery stores. My husband keeps forgetting it is the absolute best and one of the few that work. Other products bought usually do nothing. Just buy the cheap Terro Liquid, squirt a coin sized drop where ants are most often seen. They love it and will call their friends to circle around the drop and drink up. And they will survive long enough to bring it back to nest and share it, killing the whole colony. It has worked for me every time, and quickly!
I’m concerned about the toxicity of this product (Terro Liquid). Borax is about 5% of it according to the label and the other 95% is not listed. What are they hiding?
I wouldn’t buy it and certainly would never use it inside my home unless I knew exactly what these ingredients are.
I understand your concern. I’m extremely cautious around chemicals that are deemed ‘safe’ because I’m sensitive to almost all of these kind of products. But Terro Liquid doesn’t bother me at all just as the Borax I sometimes use in my laundry doesn’t bother me.
I can’t know for sure but am leaning that Terro has a propriety formula that is the perfect form of boric acid along with the best ratio of sugar to be most effective. The mysterious 95% could just be a way to protect that. Mixing up your own is the best way to be certain what you are using but I think Terro is ok. My homemade’s have been hit or miss while the Terro has had a perfect record.
I don’t trust any company that hides its ingredients. I would never buy it. A “perfect record” is another red flag of stealth chemicals in there somewhere.
In the last week I’ve seen two Queens inside the home. (Yes, I know exactly what a Carpenter Queen looks like.) That means we have a nest inside the wood of our home. Small ranch-style over a cement basement, the whole structure is wood.
I have no idea where they are hatching from, to establish a new colony. Both were found later in the evening in the south end of the house.
Ants are interesting and cool, but I am terrified by them; Carpenter Ants in particular.
Pest control time? They need to go now!
What about pets? Is this poisonous to dogs? Can I use this around the perimeter of my home? Thanks!
This remedy is for indoors and you need to keep pets away as suggested in the article.
I’m at the point where I see them randomly around the house, maybe a dozen over the last few days, and a lot outside in the garden. Where would you suggest I apply this mix to nip the infestation in the bud?
Try to see where they are trailing from so you can place bait as close to the source as possible. You may have to watch closely for a few days to get an idea.
Do I need to have the mixture moistened at all or just dry with the 2 ingredients? if I need to moisturize it, how do i go about that?
Please does rubbing alcohol work for bed bugs?
Here’s how to get rid of bed bugs. https://www.thehealthyhomeeconomist.com/natural-effective-bed-bug-removal-methods/
Can Borax be subbed for Boric acid? Thanks
Borax would not work the same.
This seems very strange! Why would you put ant bait in a dishwasher?
You did not say the reason why so I cannot connect the logic.
Anyway, thanks for the recipe. I will try it.
I put the bait in the dishwasher because that’s where the ants were coming from … they were trailing in from the dishwasher drain. Of course, I didn’t run the dishwasher while the bait was in there!