Fire Ants coming into new house from under foundation - any solutions? (2024 Update)

[Alex]

We have a crazy problem with fire ants in our 6 month old house. It started out a month ago when we found the garbage in our master bath covered in fire ants. I sprayed Ortho Home Defense around the tub then walked outside to find where they were coming in, but no trails going up the foundation. So the next day we found more in our closet and in the second bathroom (which backs up to master bath). I sprayed in there and the ants migrated to the bedrooms hitting our kids and ours then the laundry room.

I sprayed each room as I found ants and called a local exterminator to come help since all this time I hadn't seen a single fire ant coming into the house in the foundation or any nests near the house. We had some fire ant beds in the yard, but none near the foundation.

The bug guy came out and dusted the attic, sprayed the house and yard, and baited the yard (this is now a week since the first outbreak in the master bath) and for about a week this seemed to do the trick. We saw some stragglers which was to be expected, but nothing big for a few days. Then two separate days we had a line of ants going into our living room from an exterior wall. I sprayed more Ortho and checked outside, and as before nothing... no ants coming into the foundation were seen. The day after this they moved into the attic and were coming out of a near by air duct which was just freaky!

I called the bug guy again and he came out and put gel bait outside the house above the foundation and said they were probably attracted to the moisture in the air duct which is why they went up there. We continued seeing them coming out sporadically for a day or two, but I put some Ortho on a paper towel and rubbed it against the vent which seemed to stop them.

We were then bug free short of a few in the bathrooms at times for about another week then our kitchen was hit, which is on the complete opposite side of the house from any other area that's been hit to this point. Our sink sits on an island surrounded by two pillars that go floor to ceiling, and literally hundreds of fire ants were coming out from a small hole where the countertop, wall, and backsplash met and were attacking the sink. I wasn't sure if they were coming from that attic or what, but the bug guy said he's pretty sure they were coming up from the pipes in the foundation. He dusted in the hole then behind the sink where the pipes come up plus in both bathrooms. We haven't seen any ants in the kitchen, but on Monday we had an invasion in our front bathroom from under the baseboard that's opposite of the toilet, sink, or tub. The bug guy had told me not to use Ortho since it could counteract what he put down, so I just soaked the floor in Clorox Bleach bathroom cleaner and that did it... I haven't seen any more there since that night.

Since then we've seen a few in the other bathroom plus some dead ones in the living room where both the bug guy and I have sprayed, so I think they're still trying to come in. But the thing that sucks is still I've seen zero ants in the yard or on the foundation. I walk the house inside out several times a day, and outside seems to be doing great.

So my only conclusion is they're either in the attic or in the foundation, but I'm leaning more towards the foundation. So with that is there any chance in getting rid of them??? I'm literally to the point of cutting holes in the walls to expose the pipes and where they enter the house so we can cover it in ant bait or poison in hopes that does the trick. The dust the bug guy put down was just sprayed behind the cabinets, but I want to bait the things so they'll take any poison back to the nests and kill the suckers.

Has anyone ever heard or seen such a fire ant invasion? We're in Central Texas so fire ants are common, but I've never heard of them this bad. The bug guy said he was dumbfounded and would have someone with more experience with fire ants come out, but in the mean time I'm at a loss on what we can do. It seems these little turds can literally come out of any place in the house at any time, and with a

3yo and new born that's scary.

Thanks for any advice or suggestions... And sorry for such a long post, but hopefully this gives anyone with experience with pest control some pattern's I'm missing.

Sam Alex

[dadiOH]

Concrete block house? Ants live inside the empty block spaces.

Window openings finished with pieces of drywall? Ants often nest in the space between the DW and block (or frame).

BTW, not saying yours aren't, but I have never seen any fire ants inside our house or any other (central Florida). Ants, yes; fire ants, no. Our house is quite tight and we have little problem with ants, just occasionally. Ant trap for a few days and they disappear. Until the next time. Basically, you can fight and control 'em but you can't beat 'em.

[norminn]

An infestation like that with little ones in the home is truly scary. We had them in Florida, but very few coming into the house. When they did come indoors, it seems they did so only in spring. The came in when we had sweets or butter on the counter, but also headed for the kitchen drain. They followed a long trail, coming in through small gap in patio slider, through a kitchen cabinet and up the phone cord onto the counter, across counter and into sink and drain. They will go anywhere there is a trace of food. We used Amdro outdoors and brand-x liquid bait (sugar/boric acid) indoors, with good results. You might contact your county extension service for advice...would address the matter with haste and special concern for the babies.

[gfretwell]

Spray is largely useless on ants. Bait them.

[JIMMIE]

Most poisons I tried for ants were worthless. The last time I had my house treated for termites the exterminator used Termidor and I havent had an ant problem since n the yar or house. The exterminator says part of the sucess is due to just about everyone in the neighborhood using Termidor for temite control.

Jimmie

Jimmie

[hrhofmann]

Is your house on a slab with the pipes going thru the slab, or on a crawl space. If crawl space, have you gone into it and looked for where the ants are originating. Until you eliminate them from under the house, anything you do inside the house will just make them move to another entry point.

[Bob-tx]

We are in Central Texas as well, and fire ants are a real problem all over the area. We have not had them invade the house though. We have a slab foundation, so that probably helps. We have had dozens of fire ant mounds on the lot after the occasional rains (we have about one and a quarter acres). Over a couple years, we have pretty well gotten rid of them using Amdro (sp). We just sprinkle a couple teaspoon full on each mound and don't disturb the mound in any way. They apparently take the food into the mound and feed some to the queen which makes her sterile. So, it doesn't kill the ants, it just makes the mound so no more ants are reproduced, and they die off naturally.

Obviously, this is not a quick fix, but I would think that if you have ant mounds around the house, that doing this on a regular basis for about a month and periodically as you see new mounds, that it would take care of your problem. Hope this helps.

Bob-tx

[J]

A .22 rifle will cure the problem for good. The smell will linger for awhile but that's life!

J

[norminn]

No way in hell would I go into a crawl space with an infestation as the OP described....fire ants attack en masse, before you know they are on you.

I've read stories, a couple of times IIRC, of nursing home patients in Florida being found with fire ants all over them. Not something to mess with when there is an infant in a home with a severe infestation.

[norminn]

We used Amdro in our condo lawn, prior to which we could not do landscaping or work on irrigation repair. Applied properly, Amdro was taken up almost immediately - sprinkle around mounds without disturbing the mound and we watched the ants take it to the nest. Interesting to watch :o) Amdro instructions advise broadcasting, but we found fire ants almost always nested along/under pavement (patios, walks, pavers) and one application rid the lawn of problems for about a year. From what I've read, it sounds like Texas has a lot more trouble and heavier infestations than Fla., perhaps because it is drier.

[AngryOldWhiteGuy]

We have a house on a slab in North Texas - near Dallas - it's an older house, and we moved in about 7 years ago. Before we moved in, I gave the entire inside of the house a good spraying of Home Defense or something like that, and on the outside of the house I put down a liberal dose of the granules that you can put on your lawn with a broadcast spreader or you can spread them around the perimiter of the house. But those remedies arr relatively short-lived - they'll kill what's there, but there's not a real long kikk effect (not more than 3 - 6 months).

What I believe made the biggest difference was putting some of that white or blue roach powder (it's good for ants, too) around any area that I could get to where a pipe comes up through the slab - behind bathroom cabinets, under the kitchen sink, under kitchen cabinets, behind the clothes washer, behind the fridge, and behind the stove, etc. - as long as it stays dry, it seems to keep the crawling things at bay - we haven't seen but a couple of ants in the 7 years we've been in the house. You can spray the powder into areas where you can't see - like into the hole in the back of the bathroom cabinet where the water pipes come in to service the sink.

I have recently seen very good results with Terro, too - it seems to work inside and outside - it's a bait that they take back to the nest, but suprisingly, it, too is based on borax - like the roach powder.

[lj]

..

We have small black ants that always want to come in the house. They will setup a nest almost anywhere in just a day or two. Under a potted plant on the deck, anything. I bait with homemade bait mixture using karo and borax. The formula is all over the web. Sometimes you have to tweak the borax amount. Less takes longer to kill them but too much and they will avoid it. They take it back to the nest and in a few days that's the end of them. I just put a blob on a square of cardboard and put it as close to the entry point as possible. Once they find that as a food source they don't wander around anymore, they just go back and forth to that. In a couple days they stop showing up. If sugar doesn't interest them you can substitute peanut butter for the karo. All ants will go for sugar or protein. It's super cheap too.

[Steve B]

Three things that worked for me. Amdro, the little square bait modules, and boric acid mix.

All can be had at HD or similar. I got a deal on about 8 24 oz bottles of sealed Amdro the other day for $2 a bottle. It works good.

The square little things are good, too, but you have to be careful because little kids and pets will chew on them. Same thing, they take it back to the nest, and it kills the nest.

Boric acid is cheap, and you mix it with various substances like sugar, honey, and such to make your own little bug bombs. Effective, and relatively safe.

Sounds like you have disturbed the hillside and provided soft ground for incoming new queens to dig a den.

Fighting ants is going to be a constant battle, so just figure out what you're going to use, and USE IT ON A REGULAR BASIS. You may only get a perimeter around the house, and out twenty feet the hills start. There's a new flight of them frequently with new queens hatching out.

HTH

Steve

Heart surgery pending? Read up and prepare. Learn how to care for a friend.

[Bill who putters]

Go to your local drug store and purchase Boric Acid powder. Mix 1 teaspoon in a cup or two of sugar. Apply 1 tablespoon of mixture in a few containers in your basement preferably along the sill. Out side place under a flat rock. End of story. May have to repeat the outside if rains washed it away. Inside protection lasts for years. I also place a eyedropper of oil of pennyroyal on the sill once a year spring. Don't use pennyroyal in living area as it smells great but soon becomes cloying and it lasts.

[RogerT]

[Red]

Fire ants tend to swarm at night right after a rain. (I have no idea how they develop wings so fast). When they're swarming they are attracted to lights in the house and will come in around windows & doors, anywhere they find a crack. So if you can't find a obvious entry point for them, this may be a possibility. I spent many nights this summer with the main lights off and using shaded desk lamps after I got infested like you describe.

[Alex]

Hey guys --

Original Poster here , sorry for taking so long to reply back. We're now 5 weeks after our first outbreak, and the ants are still here. We went almost a week with only seeing one or two which I thought were stranglers, but turns out this evening we had a line of ants forming in both bathrooms.

Our house is on foundation, and I do think they're coming in from the bathtrap under the garden tub in the master bath, so I'm planning on taking the front of the tub off to see what it looks like. I'm waiting to hear from the builder to see how to best do it so we don't mess-up the tub, but hopefully it just pops off --not sure. I've also been in contact with our bug guy and I hope we can arrange a time for him to be here when I remove the side of the tub.

What makes me sick is since day one of being in the house I've sprayed ortho home defense outside the house plus sprinked amdro 3-4 feet around the house almost monthly plus I keep the grass cut and trimmed so I feel like I've been diligent in trying to keep the house bug free but to no avail. Originally it was more so to fight the spiders, but honestly I've seen zero ants or anything else in the yard in over a month. The ants are coming from inside or under the house there's no question about it.

It's like being a prisoner in your own home, and always having to keep our guard up. Every night I walk around the house with a flashlight, and even after a week of not seeing much this evening I saw them back in droves in both bathrooms. It's quite frustrating...

I'll post updates as I talk to the builder and bug guy, but if anyone's had fire ants like this I'd love to hear what you did. I've talked to others in our neighborhood, and they've mostly had sugar ants which these are definitely not.

Take care,

Sam Alex

[norminn]

Fire ants have been known to nest in electrical panels and other odd places...eliminate food, water and shelter. If you've identified their trail, bait should be placed alongside the trail. Caulk where they enter/leave the bath....more likely they are coming to the trap for water or food. Dump some poison in the trap, caulk along baseboards and elect./plumbing entries. Got pets? Pet food is major attractant, and crumbs usually available. Also, with small children, food crumbs and spills more common.

[Alex]

We keep a clean house even without the ants, but since the outbreak we've been especially careful not to leave any crumbs. Only once did a trail form in the living room going to some food our daughter dropped, but outside of that they seem to be hitting the bathrooms with on single item being attacked.

I've been closing up any spaces where they've come in, but it seems as soon as I close or treat one area they just find someplace else. We talked to the builder today, and the foreman is coming by today to show us how to remove the side of the garden tub. I'll have my wet/ dry vac in hand to vacuum up any mound or ants under there, plus I'll have a bucket of Amdro to spread out under the tub and around the sand trap. Also the front bathroom bathtub/shower backs up to a closet, so I'm going to get a plumbing access door and put in the closet so I can occasionally check out behind that tub and treat as needed. We've also had an outbreak in the kitchen, but I hope the ants were just following the pipes from the master bath since after the bug guy dusted under the sink we've not seen any more there.

So that's my plan... The yard has been bug free for a while now, so hopefully if we can kill what's under the house there won't be any more problems. I'm keeping my fingers crossed anyway :) What's nuts is I've not heard of anyone in our neighborhood having this kind of problem, nor have I seen any articles or posts like mine. Is this just an isolated 'worse case' scenario with fire ants? Even before the outbreak we've heeded all the warnings treating outside, keeping floors clean, keeping yard cut, etc, so honestly I can't think back to anything we've missed that would've brought on this invasion other than just bad luck and the builder not treating for ants before laying the foundation (they did confirm they treat for termites but not ants).

Anyway, there's my tale of whoa :) I'll post updates as we investigate under the tub plus some pictures if there's anything worth seeing.

Sam Alex

[BobR]

I tried to resist but it was just too much to ask......

FIGHT FIRE WITH FIRE!