Killing fire ant colony under house - concrete slab so no crawl space

My BIL's turkeys love to find a fire-ant mound and eat all the ants.

But would fire ants nest under a slab? I thought they needed mounds for solar heat.

If they _are_ fire ants, they may be helping you. They could be eating a nest of termites in wood buried under the slab, and they come up for a drink. When they finish eating the termites, you could look for their mound near your house.

I keep a one-quart pump-up sprayer with about a teaspoon of termidor concentrate in a quart of water. When I find a mound, I squirt about a tablespoon of the dilute mixture on a spot in the middle of the mound. If I kick the mound a week later, there will be no response.

That price is for concentrate. It is mixed with water. All the drilling, appllication, filling the holes cost me aound $1000. Took care of ants termites and a lot of other insects including roaches and crickets. Still works after 10 years. Works best if your neighbors also have their homes treated with Termidor.If he came in with a little sprayer and spritzed the stuff around he is ripping you off. Doubt if he is even applying Termidor.

Jimmie

Are you 100% sure they are fire ants? Been stung? What state are you in?

I stopped drilling holes for termites ~1990. I found that using 4-6' "stingers" I could effectively inject material around basement walls/ under slabs.

My problem with Termidor is that it is a "stealth" insecticide, so it doesn't provide the repellent effect you get with nearly all other materials. You drench the mounds in your yard and the ants are likely to take off in any direction, including toward the house.

I would bet you could get acceptable results with the bifenthrin trade named Talstar P (/Talstar One) diligently applied with a garden sprayer (according to label directions).

If you anticipate future battles I'd recommend you get some. I buy

Checking, it looks like this guy is right; you'll be hard pressed to find a better number than $47.95 and free shipping.

- gpsman

Yes he used the 20oz bottle of Termidor, I saw the bottle and read the label. He targeted the ants under our garden tub coming up from the sand trap, and as expected within a few days they were gone from there, but I think they've moved to a second bathroom around a toilet that we've found to have a leaky seal which we're getting fixed this afternoon. Termidor can't be used around the toilet, but I hope by replacing the wax ring and also caulking around the toilet drain that'll keep them away from that area. And if this is their primary source of water under the foundation and it's removed maybe that'll drive them away.

Also if you got your house sprayed 10 years ago, termidor was just introduced in 2000 so you were one of the firsts :) And if it cost you $1000 them I bet it'd be MUCH more today. But if after fixing the toilet and baiting the yard once more (it's been 3 months since it was baited last) and the ants are still around, I'll see if we can go with under the foundation treatment regardless of the cost.

dadiOH

-- Are you 100% sure they are fire ants? Been stung? What state are you in?

Yes they are, and yes I have, and we're in Central Texas...

Before we found the primary source of the ants we had them literally in every room of the house, even in the ceiling (attracted to moisture in the AC vents). Me, my wife, and daughter got stung several times during that fiasco, but since having the sand traps sprayed they're just trickling in... no lines of ants, just one or two here or there. When it's damp outside we get a break from them, but given a few days of dryness we see worker ants coming back in. I've sprayed around the bathroom parameters with Ortho Home Defense which keeps them isolated to the bathroom. Like I said before hopefully fixing the leaky toilet will remove their source of water and make them move elsewhere.

Are stingers those pipes that can be inserted into the foundation and chemicals poured into to disperse under the foundation? I've heard of people doing that but I've not heard that term used. Also for is it'll be tricky since all our pipes are under the foundation, so whoever does it will need to be careful not to puncture a pipe or we'll really have a mess.

But yeah I know that about Termidor being a stealth pesticide, which is one reason our bug guy is using it. Problem though now is with the trickle of ants coming into the house I don't know if enough are making it back to the colony to do much good. Under the tub we had hundreds coming in, so I think spraying there really hurt if not for the most part destroyed the colony. I think/hope/assume what we're seeing how are the left over ants possibly making a new colony under the toilet with the leaky seal which will be fixed this afternoon. If that's the case then hopefully flooding that area around the toilet pipe with Ortho Home Defense (don't want to use a bait) then caulking it, then resealing the toilet to avoid more leaks will kill those there and remove their water source.

And yeah once the ants seem to be somewhat gone I'd like our bug guy to spray whatever he has to do around the pipes to kill whatever worker ants start coming in, whether it be dust or something stronger. My fear though is that the pipes come up through the stud footer on the concrete, so unless whatever is sprayed is able to soak down into that, the ants can still come up under the stud. Not sure yet.

But I'll post back after the plumber leaves with news of what we find under the toilet.

Also note to whoever suggested it, I did talk to our county extension office, and after telling them everything that's happened they said they've never heard of fire ants being this aggressive in our area or otherwise. The person I talked to is sending the details to an expert in urban ants (or something like that) and they'll follow-up with me with more info.

So again from this and everything I've read our case is rather unique...

Fire ants are a huge problem in Texas, especially with livestock, so there should be plenty of expert help available....in Florida, they aren't often an indoor problem, but treatment methods are common knowledge. Since yours seem to be seeking moisture, that is what I would focus on...as with termites, KEEPING THEM OUT is most important, although lots of folks seem to think they need to kill all in the neighborhood. Caulk everything that can be a point of entry (plumbing and electrical entries), cracks around doors and windows, all baseboards (esp. in bath and kitchen).

Sprinkle bait in your "sand traps" and any entry points presently in use. Amdro is an excellent BAIT and effectively changed our yard from unuseable to comfortable - got attacked rather badly a couple of times working on irrigation sys. outside. Once knelt on a nest and before I realized they were on me, they had swarmed - over 100 bites on one leg. That seems to be their trick - I normally feel any bug that touches, but there were hundreds on my leg before I felt them and they seem to bite in unison. A lot of advice from people who have never experienced them, and general advice about ants does not really apply. There have been a couple of "mass attacks" on nursing home patients in Florida - not something to mess with or trust to amateurs. We used Amdro where we found the sites fire ants favored - along walks, pavers and patios. Label advises broadcasting, but for us it was not needed. We used it pretty sparingly and took care not to hit the nest . sprinkled around the opening, it didn't take long for them to start taking the bait. Pretty interesting to watch, as well.

I've never understood the reason for leaving slabs open underneath bath tubs, but caulking a hunk of plastic over those openings would at least discourage the ants.

Something I found on Termidor that may explain your experience with it:

Termidor is made to bond to soil and will only last extended periods of time when placed into the ground for termite control. Also, when you treat in a trench in the ground for termites, you are pouring in 4 gallons per 10 feet. Termidor will only last for 10 years when applied in a trench for termites. When you use Termidor as a spot treatment indoors on wood, it will only last for 6 weeks at the most, because it is not made to bond and last on wood, it is meant for soil treatments. Although you can use it indoors for spot treatments in wall voids for termites only, you cannot use Termidor as a pest control spray indoors.

Jimmie

My experience agrees (though I'm in Florida, not Texas). Your theory about water-seeking seems sound, except that it's highly unusual in my experience for fire ants to be found inside isolated from a nest. I would work hard to locate the nest or nests, which are probably out in a sunny area -- these ants do not like shade. (In fact, where I used to live, the ants gradually retreated as the trees grew and shaded them out.)

If the weather has been dry, you may not see the classic mounds. The ants only build the mounds when the soil is sufficiently damp. The nests can be flat on the ground until then.

Very good idea. In particular verify the identification. In the southern US, "fire ant" usually means Solenopsis invicta, the South American invader, but some people use the term for any stinging ant. Did the stings you received result in white welts, that look like large pimples, after 24 hours, and take a couple of weeks to heal? That would be strong evidence that they are indeed S. invicta.

However, the unusual behavior -- coming inside so aggressively -- merits making sure of the ID.

As for Termidor, I gather from reading that it's intended to soak into wood and soil. Though approved for ants, this action is more appropriate for termites, and the approval for ants is recent. The active ingredient, fipronil, is sold in bait form, but Termidor is not a bait. It may be that the ants are not taking enough of the fipronil back to the colony to kill the queens and that the colony quickly regenerates, and then follows paths which have been "cleaned" of fipronil.

Yes, queens, plural. Unlike many ants, fire ant colonies have multiple queens, making them more resilient.

Interesting tidbit found on Wikipedia: S. invicta was first identified by E O Wilson, the famous ant expert -- when he was 13 years old.

Edward

Jimmie,

Can you send me the link where you read this on the Termidor site??? Also for others who have used Amdro, with it being dry out the ground and foundation have separated so would pouring Amdro or some other bait in this area in a decent quantity maybe draw them out from under the house to 'feed' and maybe they'd carry it back to their nest? My fear though is that it would attract more ants which would be counter productive. Our bug guy has been treating outside with granular bait sprinkled around the house, but I'm thinking it might take a generous quantity to entice the ants under the house to come out and grab some.

I've sprayed Ortho Home Defense around the bathroom counters so though they're crawling out they're dieing pretty fast, so I hoped they'd eventually give-up and look elsewhere for food/water, but thus far no dice. It's definitely not the invasion it was a few months ago, but I want to get the ant count to zero, not one or two a day.

Thanks for the great info...

Plumber came out on Friday and pulled the toilet, but it was clean -- no leak. We flipped the toilet over and I didn't see any evidence that there was a leak or even any ants which I wasn't expecting. So that theory went out the window.

In talking to our bug guy about it and he said if the toilet seal was made of bee's wax that could've been attracting them. I had the plumber caulk the outside of the toilet though so if they were attracted to the wax ring maybe that will cut off that food supply. Though I have the baseboards in that bathroom covered in Ortho Home Defense I haven't seen any in there since early last week and none since the toilet was resealed and caulked.

I do however see about 2 or 3 a day in the other bathroom, though Ortho Home Defense is killing them as soon as they get out. My only fear is this this bathroom backs up to one of our kids rooms, and though I haven't seen any in there yet I can imagine there's more coming up that I'm not seeing. Our bug guy is coming out this week to spray Termidor inside the wall behind the sinks so maybe that'll help. The only thing he's done back there thus far is dusted, but I don't think the dust got deep enough to do much good.

Jimmie,

Can you send me the link where you read this on the Termidor site??? Also for others who have used Amdro, with it being dry out the ground and foundation have separated so would pouring Amdro or some other bait in this area in a decent quantity maybe draw them out from under the house to 'feed' and maybe they'd carry it back to their nest? My fear though is that it would attract more ants which would be counter productive. Our bug guy has been treating outside with granular bait sprinkled around the house, but I'm thinking it might take a generous quantity to entice the ants under the house to come out and grab some.

I've sprayed Ortho Home Defense around the bathroom counters so though they're crawling out they're dieing pretty fast, so I hoped they'd eventually give-up and look elsewhere for food/water, but thus far no dice. It's definitely not the invasion it was a few months ago, but I want to get the ant count to zero, not one or two a day.

Thanks for the great info...

I posted some links a few messages back which gave some very useful information....one bit that I had not read before was that fire ants eat only liquids....Amdro's formula takes that into account, containing oil of some sort (don't recall all the details, but it was an authoritative source. You keep mentioning moisture...one thing that might attract ants indoors, aside from water, is toothpaste, especially in kid's bathroom. Learned that with other ants. If you see live ants indoors, you can certainly follow their trail...that's all you need to do to lay down Amdro bait. My experience is that they go after Amdro rather quickly, and it rid us of fire ant problems in our lawn .. may not have killed every ant, but we were able to do a lot of yard work without being swarmed and attacked, it took relatively small amounts and it lasted about a year. I don't think that covering the entire interior with insecticide will be as effective as solving what ATTRACTS them and then baiting near their trails. Cleaning up sweets and greasy stuff around the house is important, too.

I'm sure that you will not rid the entire property and under-foundation of ants...just treat for the ones that are entering the house and correct the issues that attract or allow entrance.

They do carry Amdro back to the nest...that's the entire purpose of it. It is bait that contains poison and hopefully is carried back to the queen, too. Ya' can't control how many in the nest die, but you should be able to kill of most of those that are foraging IN YOUR HOUSE. There is also concern that you kill off beneficial insects by overdoing the poison....lots of contractors will sell you everything you wish to buy, not necessarily what you NEED.

I'm thinking that any pest control contractor in either Florida or Texas who can't get rid of fire ants on the first go 'round might not know what the heck they are doing. Fire ants are so common both places that is really well known. Another spot that I forgot to mention is fire ants nesting in electrical boxes...saw it mentioned again in one of the articles I posted. Reason not known, but it is fairly commonplace. Another treatment/bait mentioned is peanut butter mixed with boric acid...works nicely for roaches, too. We got $500 worth when we had our Florida condo treated for roaches :o)

NorMinn,

Thanks for the info, and you're right on the toothpaste was something they = did attack in our front bathroom. We have a medicine cabinet in the wall, = and before we found the mass flow of fire ants from the sand trap they were= attacking this area in masses which we did have toothpaste, mouthwash, etc= in there. Also since we caulked up around our front toilet I haven't seen= any in the front bathroom (knock on wood) because I'm wondering if they we= re attracted to the wax seal under the toilet. Go figure...

Our bug guy is coming out tomorrow to spray a different chemical in the wal= ls where the pipes come through the foundation since the ants are just a tr= ickle, so that should hopefully kill the few that come in that way on conta= ct plus he'll heavily bait along the sides of the house near the foundation= , so with this plus the Termidor in the sand traps hopefully that'll do the= trick.

I'm definitely seeing a pattern though because it's been humid and moist ou= tdoors the last few days (not rain, but we have a heavy dew in the morning)= and I've not seen any ants in 48 hours. So hopefully they're coming out f= rom under the house to find moisture so maybe just maybe the bait we put do= wn tomorrow will help.

But unfortunately we've gone a week or two without seeing any ants then the= y come back, so I won't celebrate until we've gone months without seeing an= ts. Just sucks because given they've gotten in once I assume they could al= ways get in again given the chemicals don't last forever.

Fire ants are definitely very common, that is true, but from what I've seen= and read the type of outbreak we have is rather atypical. Even the folks = at our local county ag extension office haven't heard of such an indoor inf= estation of fire ants like we have before. Our bug guy treated the ants as= if they were coming from the walls by baiting outside and spot spraying in= side, and we've not seen one single ant in the yard since... so yes that is= working. But in our situation they're under the house which takes more wo= rk. Until we found the massive line of ants from the sand trap there never= were trails to bait per say. I would see a few here or a few there, but t= he few trails I saw were always at night or early in the morning when the b= ug guy wasn't around.

But Termidor in the sand traps has worked with the infestation, but given t= here's still paths for ants to come in through the pipes in the foundation = (and their enzyme trails are now all over the place) we still have worker a= nts coming in all too often. So hopefully with more aggressive chemicals u= sed in the walls where the pipes are that'll kill the few worker ants that = do try to make it in and hopefully detour them all together eventually. I = don't know how long it takes an ant colony to die out without water or food= , but given they have zero ways to get inside hopefully they'll move elsewh= ere if the bait outside doesn't do the trick sooner.