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

[Malcolm Hoar]

My experience is with common (not fire) ants but most of the same things apply I think.

1. Like you, I try to lay down a protective barrier around the perimeter of the house. However, you need to check for overhead pathways too! These suckers will enter the home via overhead cables, even via a tree that happens to touch the house at a single point of contact (20 ft above the ground). Now I spray around the roots of any trees near the house.
2. Sometimes we find a colony that is clearly nesting inside the house (nothing entering or leaving the perimeter). Repellant sprays are a waste of time. They just move around them. Making a mix of food and poison usually fixes the problem in 2-3 days.

I use boric acid with sugar solution and boric acid with mayo; see which they prefer (sugar or fatty diet). I aim to mix food:poison in a 7:1 ratio but don't bother too much about precision.

[norminn]

I lived with fire ants in Florida for quite a while, so know their bite well :o) From what I've read, they are a far more serious problem in Texas....because our condo grounds had quite a severe infestation, my hubby and I began researching methods to eradicate. Found Amdro worked wonders....hubby was the handyman/building manager, so we did lots of work, like repairing sprinklers. After treating with Amdro, they seemed to disappear for about a year. They were never an indoor problem, as far as I know. We found that they infested areas along pavers, patios and walks. Probably nests were more protected from rain in those places. We never broadcast Amdro - it took very little, sprinkled around mounds, to get rid of the mound.

You might have been lucky enough to have had construction workers leave behind food...never know what you'll find inside walls. Be sure to have annual termite inspections...fire ants like to dine on termites and other bugs.

[Alex]

That's what I'm afraid of... Another house in our neighborhood is in the process of being built, and with the bathtub side still off I could see all sorts of soda cans and garbage thrown under the tub. Surely these would've been cleaned out before sealing it up, but if we remove the side of our tub and find things like this I'll be calling the builder asking for compensation for the pest control.

Sam

[Stormin Mormon]

At my church, I found a couple soda pop bottles in the sewer vent stack. A design of bottle I'd not seen in 20 or so years. Glass bottle, with foam wrap. 16 ouncers.

[norminn]

I don't know how builder warrantees work, but I would sure take photographs and document dates carefully. Wouldn't hurt to write a NICE business-like letter to the builder, certified mail, and state the issues clearly. Mention fire ants and newborn baby living in your home. Is your pest control person licensed, insured and good rep? Certainly the county extension service must have LOTS of experience and information about fire ants - in Texas, they are a major problem for livestock.

[Alex]

I'll have a camera on hand when we remove the cover from the tub, so everything will be documented... but more so to show others who might be facing this problem what we've gone through. This has been the most frustrating thing I've had to face in a long time.

As for contacting the county extension service, what services can they offer? I visited the website for our local office, but I wasn't sure what to ask if i contact them other then asking for general advice to see if we're on the right track.

[Alex]

An update on our ant problem for anyone following this or running into a similar problem.

The bug guy came by this morning and we removed the side of the garden tub in our master bath, and as we thought/hoped there was a THICK and fast moving line of fire ants coming from the sand trap into the walls, probably about 1/2 inch wide.. Crazy!!!! The bug guy used Termidor foam and layered under the tub and shower (which is next to tub) then he poked a small hole in the baseboard of a close behind the front bathroom tub and sprayed in there as well. This morning we found ants coming from the pipes in the laundry room, so he did a small hole behind the washer and put Termidor in there as well.

With this plus his dusting behind the bathroom and kitchen sinks during his last visit I really hope that nips the problem. I'm just glad we found where the were coming from because if we would've cracked open the tub and found nothing I'm not sure what we would've done. This has been a stressful ride, but I hope it's about over. The bug guy said we'll see some ants but as the Termidor breaks them down from the inside-out they shouldn't act right -- which I just found an ant walking in circles and twitching in the laundry room so that's good.

Anyway, hopefully our ant saga is about done. Take care --

Sam Alex

[Flip Hitchcock]

OP Here --- It's been three weeks since the bug guy came and sprayed the sand traps under our two tubs and shower with Termidor, and we were ant free until a few days ago. On Sunday while cleaning our front bathroom I found one fire ant, then another, and another, and since then I've killed maybe 15-20 ants in the bathroom. No trails, just a trickle of ants from either where the sink or toilet pipes come into the house through the foundation. The bug guy dusted behind the sink a while back, but he's coming back out on Friday morning to hopefully spray Termidor into the wall where both pipes come through the foundation. And if he doesn't mind I'll have him do the same for the other bathroom sink and kitchen sink. After this hopefully all our foundation pipes will be treated with Termidor which has worked thus far.

My biggest question now is how often should I expect to go without seeing more ants, because no chemical lasts forever, and if they found their way in one they'll get in again. Quite frustrating knowing these pests can pop-up anytime, and I just wish there was some way to seal the pipes permanently so they couldn't get in. Anyone know how to kill them under the foundation? My fear is that the ant trails are now in place under our house, so it's just a matter of new colonys finding their way inside as the chemicals get weaker. I've not seen one ant mound or even an ant in our yard in months, so I know they're living solely underground. What the heck??? Is our house built on a super colony or something?

Thanks --

Sam Alex

[Alex]

OP here again with another update.

We went through January, February, and much of March seeing very little act= ivity, just a couple of ants in all, but now that it's getting warmer we've= started seeing more. In walking around our neighborhood I've seen other h= ouses have the sand traps filled in with concrete so I've talked to our bui= lder who has said they'll come out and fill in both sand traps with concret= e which should hopefully stop our influx of bugs.

So a note to those with either an inside bug problem or having a house buil= t -- have your sand traps filled in under all bath tubs! It'll save you pl= enty of grief :)

Sam Alex

[mm]

activity, just a couple of ants in all, but now that it's getting warmer we've started seeing more. In walking around our neighborhood I've seen other houses have the sand traps filled in with concrete so I've talked to our builder who has said they'll come out and fill in both sand traps with concrete which should hopefully stop our influx of bugs.

have your sand traps filled in under all bath tubs! It'll save you plenty of grief :)

o Spray with ant killer? I just sprayed one section of the trail of some ants my kitchen, 3 feet out of a lot more, and they disappeared for almost a year, over a year maybe. They have scouts and the scouts have standards.

[Shah]

replying to Alex, Shah wrote: Hi Alex,

We are having exact same problem in our house. We are in Central Texas too. how did you remove Fire ants from your house?

[Ralph Mowery]

Best thing to do is get some of the powdered fire ant bait and put it out. They carry it to the nest and they all die. Especially the egg laying queen.

[hrhofmann]

Can anyone explain what a "sand trap" is? The OP mentioned it a couple of times, but I know of the term only as relating to bad golf shots.

[clare]

From the plumbingsupply webpage:

These sand and sediment interceptors are designed to separate and retain sand, gravel and similar materials, in addition to any oil, grease, gas or diesel fuel-laden waste material. This is accomplished through the principle of gravity and flotation separation. The separator's eight chambers, with varying passage elevations, trap virtually all solids which separate from water under gravity conditions. Larger and heavier materials are retained in the first compartment, while smaller and lighter materials are trapped in other compartments. Oil, grease and similar materials will be retained at the surface of some or all eight compartments. Any gaseous fumes will be collected between the top of the water and the bottom of the cover and vented through the 4 individual 2" threaded vent connections. These sand / sediment interceptors are constructed of fabricated steel and have an acid resistant coat for durability.

[KZ]

Hi, Alex.

I'm a fellow Texan and just found your 13 year old post going down a google rabbit hole trying to find a solution to the same problem. I have no idea if you are still active or if you will ever receive notification of my response, but here goes.

You are the first person on the internet in which me reading your first post was unbelievably relatable nearly word-for-word, but I'm merely in the very early stages of what you experienced. My house is only 2 years old post-construction and found sporadic fire ants in my master bathroom just like you did for the very first time this March 2024. Pest control guy believes it's coming from the garden tub plumbing, since they're coming from the carpet-tile edge at the doorway of the master bath. And then somehow in the separate shower (maybe the shower drain)? I had no idea what a sand trap was until you talked about it here. Pest control sprayed Termidor on all outdoor mounds, foundation perimeter, and under the baseboard in my bedroom that meets the wall behind the tub. Still seeing small number of fire ants but now I'm seeing the bigger guys plus the little ones!

If this comment reaches you, what's been your outcome since your battle 2010-2011? What's your advice?