Imported Fire Ants

Everything on this page comes from university extension services and, for the quarantine, from the Code of Federal Regulations. Each claim names the source it rests on in the sentence that makes it. Where two sources give different figures, both are given with the source that holds each, because picking one would misrepresent the evidence.

Which Ants the Name Covers

The scope question has a legal answer. 7 CFR 301.81-1 defines the term:

“Imported fire ant. Living imported fire ants of the species Solenopsis invicta Buren and Solenopsis richteri Forel, and hybrids of these species.”

So three things travel under the name: the red imported fire ant, Solenopsis invicta; the black imported fire ant, Solenopsis richteri; and the hybrid between them. It is red imported fire ant that is the narrow term, not imported fire ant. Texas A&M uses the same three-way construction, describing imported fire ants as those “which include the red imported fire ant - Solenopsis invicta Buren (Hymenoptera: Formicidae), the black imported fire ant - Solenopsis richteri Forel and the hybrid between S. invicta and S. richteri”.

One statement on this page is about Texas and only Texas. Texas A&M states: “In Texas, S. invicta is the only imported fire ant, although several species of native fire ants occur in the state such as the tropical fire ant, S. geminata (Fabricius), and the desert fire ant, S. xyloni McCook, which are also capable of stinging”. That is why the federal term is used throughout the rest of this page: outside Texas, the black imported fire ant and the hybrid exist too.

No source consulted tells a homeowner how to separate red from black from hybrid in the field, and none gives different control advice for them. This page therefore treats them as one management target, which is what the regulation and every extension source here do.

Telling Them From Native Ants

This matters before anything else, because several of the sources say the ants you should leave alone outnumber the ones you should treat. Clemson Extension states: “There are at least 121 different species of ants in South Carolina, and the majority of these ants are benign and do not warrant control.” It adds why that matters: “Improperly identifying a pest can lead to pesticide failure, which is a waste of time, money, and, most importantly, an ineffective and possibly unnecessary pesticide application.”

The structural character. NC State Extension states: “Fire ants are our only ants that have two bumps between the thorax and abdomen.”

On size, two sources disagree, and the disagreement is itself useful. NC State Extension gives a single length: “Red imported fire ants, Solenopsis invicta, workers (Figure 1) are approximately ¼ in long, red-brown with shiny, dark abdomens.” The N.C. Cooperative Extension Pamlico note gives a range and treats the spread as the tell: “Fire ants are small, only about 1/8 to 1/4-inch long.” and “Variation in size is a distinguishing feature as many other ant species are uniform in size.” One is a length; the other is a range whose spread is the point. Both are recorded here.

The mound, and what it does not have. The Pamlico note states: “Fire ant mounds are usually a distinct dome shape with no opening at the top, which are found out in the open, not in the woods.” UF/IFAS Extension corrects the assumption that follows from that: “Fire ant nests will not have a single nest entry, but rather, several entrances under the mound.” And the behaviour, from the Pamlico note: “If a mound is disturbed, usually hundreds of fire ant workers will swarm out and run up vertical surfaces to sting.”

The most specific character is the mark the sting leaves. Texas A&M states that within several hours to a day, most people develop “an often white fluid-filled sterile pustule characteristic of imported fire ant sting”, and adds: “No other Texas’ ants are known to cause this type of reaction to the venom.”

The Sting

Everything in this section is what one named publication says. This site is not a medical source and does not assess anyone’s symptoms. The publication it comes from opens by disclaiming exactly that, and the disclaimer is worth reading in full:

Scale. Texas A&M states: “Over 40 million people live in areas infested by the red imported fire ant in the southeastern United States. An estimated 14 million people are stung annually.”

How fast. “Generally, these ants can begin to sting within 10 to 20 seconds after climbing upon victims.” The same publication notes that response slows when temperatures are cooler than 55 degrees F, because the ants move more slowly, and when they are above 95 degrees F, because the workers sit deeper in the soil.

What a normal sting does. “The site of the sting hurts for a few minutes and then reddens; then it swells into a bump or hive within 20 minutes.” Then the pustule described in the section above. Texas A&M adds one instruction about it: “Care must be taken not to rupture the sterile pustules, because resulting lesions occasionally become infected.”

On how often that happens, one document carries three different figures, and this page gives all three rather than choosing. In its own body text, Texas A&M states that “severe allergic reactions (anaphylaxis) occur in less than 1% of people stung by fire ants.” Citing deShazo and colleagues, the same document states that “Anaphylaxis occurs in 0.6 to 6 percent of persons who are stung, and these reactions have been reported to have caused more than 80 deaths.” And quoting a Texas Allergy, Asthma and Immunology Society leaflet, it states that “Severe allergic reactions (anaphylaxis) occur in 1 - 6 % of people stung by fire ants and occasionally these reactions may be fatal”. Under one per cent, 0.6 to 6 per cent, and 1 to 6 per cent — in a single source. Any page that picked one of those would be misrepresenting it.

Texas A&M also states: “People who show symptoms indicating anaphylactic shock should seek advice from an allergist before entering known fire ant infested areas.” And, quoting Solley and colleagues: “Anyone who has had stinging-insect-induced anaphylaxis should carry an EpiPen (or EpiPen Jr for children; CSL) for immediate first-aid use, if hypotension or dyspnoea occurs.”

That publication also contains a block of treatment guidance addressed explicitly to medical doctors, naming drugs and formulations. It is named here so a reader knows it exists and who it is written for. None of it is reproduced on this page.

Who is most at risk, and where. Texas A&M names people “hypersensitive to venom or may have other medical conditions (e.g., heart condition, diabetes) that can result in serious medical problems or even death from a single sting”. It records that “Fire ants move into beds of children or immobile people during the night” and that a number of serious multiple stinging incidents have occurred indoors in Texas, and, citing deShazo and colleagues, in health care facilities.

Avoiding a sting in the first place, in the same publication’s words: “Be aware of fire ants and take care not to stand on ant nests or resources on which they are foraging.”; “Wear protective clothing during outdoor activities, such as boots and/or tuck pant legs into socks.”; and “Teach children and visitors about fire ants and their hazard.” Two situations it singles out: “Ants in migrating colonies are highly defensive and should be avoided”, and during flooding, colonies “are capable of floating in clusters or ‘rafts,’ posing a threat to anything encountering them.”

The Two-Step Method

This is the method Texas A&M AgriLife Extension publishes and the one every Texas source on this page points at. AgriLife Extension describes it as “less labor-intensive, less toxic and more environmentally friendly than most other means of do-it-yourself fire ant control.”

Step one, in the source’s words: “The first step is to broadcast a fire ant bait—a product containing a food plus an insecticide—over the whole yard, usually in the fall and spring.” The mechanism is why a bait works where a spray does not. UF/IFAS Extension states: “Fire ants are omnivorous. They eat plants, insects, oils, and sugars, but they are only able to ingest liquids.” And the target: “To eliminate a colony, the queen must be killed; in multi-queen colonies, all queens must be killed.”

The rate. AgriLife Extension states: “Follow the label. The typical application is 1 to 1.5 pounds per acre. Using more is wasteful and doesn’t improve results.” Clemson Extension gives the same figure and adds: “DO NOT APPLY MORE BAIT THAN WHAT THE LABEL SPECIFIES.”

The temperature, where three sources give three answers. Clemson Extension states: “Ideally, soil surface temperatures should be between 70º and 85º °F.” The 2003 Texas A&M publication gives 70 to 90 degrees F, and puts the season at May to September in most of Texas — that sentence is broken across a column by a table in the original, so it is paraphrased here rather than quoted. AgriLife Extension in 2026 gives a looser figure: “Apply bait when temperatures are about 70 degrees or above, when ants are actively foraging.”

Rather than pick a temperature, use the test. Texas A&M says to put a small amount of bait or suitable food — a hot dog or potato chip — next to a mound, and: “If ants begin removing the food within 30 minutes, it’s a good time to treat.” Clemson checks its potato chips after 20 to 30 minutes. On the season, Clemson states: “Make two annual bait applications; one in the spring and one in the fall. Apply baits in late May/early June and again in late September/early October.”

Rain, and the two sources give different windows. Texas A&M in 2003: “Apply baits when no rain is expected for at least 8 hours.” AgriLife Extension in 2026: “Check the forecast and avoid applying bait within 48 hours of rain.”

Where to put it. AgriLife Extension states: “Sprinkle bait around the mound’s perimeter rather than directly on the mound. When disturbed, ants go into defense mode and won’t collect bait.” NC State Extension gives the distance: “Do not place on top of mound. Foraging ants exit the nest along the outside base of the mound. Place product within a 2 ft radius around mound.”

Freshness, where the two sources are irreconcilable. Texas A&M states: “Unopened containers stay fresh for up to 2 years.” NC State Extension states that baits function as attractants and so “the product must be fresh (1-3 month shelf life)”. Two years against one to three months. The practical route through it is Texas A&M’s own test: “Sprinkle a small amount next to an active mound. If the bait is fresh, ants will begin removing it within 30 minutes.”

Three baits are named below, and they are named for one reason: the active ingredient each listing publishes is one a source names for fire ants. They are not ranked. No speed claim is made for any of them, because the sources disagree with each other on how fast these actives work and this page has no basis for choosing.

The Spreader Matters

This is the one piece of equipment the sources specify, and they specify it by exclusion as much as by type. Texas A&M states: “Hand-held seed spreaders are ideal for applying fire ant baits.” and “Push-type fertilizer spreaders put out most baits too quickly.” Clemson Extension excludes two more: “Do not use belly spreaders or drop spreaders, as the gate openings cannot be restricted adequately, and these put out too much product.”

Clemson also gives the technique, which follows from the rate: “turn the hand crank slowly and walk fast”. Texas A&M says to set the spreader on the smallest opening and make one pass over the area to be treated.

Both spreaders below are the hand-held type the sources name, and neither is a belly, drop, push or chest-mounted spreader, all of which the sources exclude. No source names a product. Texas A&M mentions two models by name in its 2003 publication and attaches this to the mention: “Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by Texas Cooperative Extension is implied.”

Step Two: Treating a Mound

Texas A&M describes the second step: “The second step is to treat problem ant colonies—those needing immediate attention—using a mound treatment.” It is explicit that this is not a whole-yard job: “It’s not necessary to treat all fire ant colonies with mound treatments after applying a bait. Limit Step Two treatments to mounds located next to house foundations, in high-traffic areas or other trouble spots.” AgriLife Extension adds that where a property has only a few mounds, it may not even be necessary to apply bait as a first step.

The criterion for this step is a volume of water, and it decides whether it works. NC State Extension states: “Must apply with considerable volume (2 gal water/mound) of liquid to reach the queen in the nest or the colony will survive.” Texas A&M gives 1 to 2 gallons per nest for both granules and liquid drenches. NC State adds two instructions: treat in mid-morning, when the ants are closest to the surface, and “Do not physically disturb the mound before or after application.”

No mound-treatment product is named on this page. The natural-products route Texas A&M describes is a spinosad bait first and then a d-limonene drench, and the listings checked for this page either did not publish a mound application in their own text or did not publish an active ingredient at all. A product that does not state the job the source describes is not one this page will put a criterion against, so the criteria are given above as content and nothing is sold against them.

Handling Liquid Concentrates

AgriLife Extension states that “Wearing proper protection such as gloves and possibly even safety goggles is key if you’re mixing chemicals.” Texas A&M is the one source that gives a specification: “Always wear chemical resistant, unlined gloves to protect your skin when handling liquid concentrates, and follow label safety directions.”

Note the scope. That instruction is attached to handling liquid concentrates, which is step two. It is not attached to broadcasting a granular bait.

The three gloves below each state both properties the instruction names — chemical resistant, and unlined — in their own listings. Listings that state one and not the other, or that contradict themselves, are not named here.

What the Sources Tested and Rejected

Grits. UF/IFAS Extension states: “Fire ants only ingest liquids, so the idea that they will eat the grits, swell, and then explode is false.” Clemson Extension adds: “First, adult fire ants cannot physically ingest solid food. Second, grits do not contain any toxicant (poison) that would kill the ants.”

The wider tested list. Texas A&M reports: “Evaluations of home remedies including aspartame, baking soda, cinnamon, club soda, coffee grounds, grits and Malt-O-Meal, and molasses failed to document control of imported fire ant mounds.” On club soda specifically, UF/IFAS states: “This method is ineffective and at most may only drown a few ants.” On soap and wood ashes: “These substances supposedly remove the wax layer that protects the ant’s body, which is not true.”

Shovelling one mound onto another. UF/IFAS states: “Multi-queen colonies are not territorial and this method is not even effective for single-queen colonies. Florida has multi-queen populations, so by following this ineffective method you risk increasing your fire ant problem.” Texas A&M agrees: “Colonies in mounds that are regularly disturbed or knocked down may move, but this does not eliminate the ants.” And the general reason disturbance alone fails, from UF/IFAS: “If the queens are not killed, the colony will not be destroyed and will most likely establish itself in another nearby area.”

Hot water works partially, and the three sources give three figures. Texas A&M states: “Approximately 3 gallons of hot water poured on each mound will eliminate about 60 percent of the mounds treated”, citing Tschinkel and Howard. UF/IFAS states: “Scalding water (190ºF-212ºF) has been used on mounds with an elimination success rate of 20%-60%. Slowly pour at least 3 gallons onto the mound, being careful to avoid getting burned.” The 2003 Texas A&M publication is vaguer and blunter about the risk: “Boiling water (about 3 gallons per mound) can eliminate some fire ant colonies. However, this method can be hazardous to the person carrying the hot water. Boiling water poured on grass or over plant roots also can be lethal to the plants.” AgriLife Extension in 2026 offers it as an organic option and warns that it “requires caution and often repeated attempts.” About 60 per cent, 20 to 60 per cent, and “some”. All three agree on roughly three gallons and all three warn about burns.

On devices sold for fire ant control. Texas A&M states: “Devices that do not use chemical insecticides or microorganisms are not required to be labeled as pesticides by the Environmental Protection Agency, and are often marketed without scientific evaluation. The fact that a ‘control’ device is on the market does not indicate that it is effective.” It says deceptive claims should be reported “to the office of the Texas Attorney General or the Federal Trade Commission.” No such device is named on this page.

Two more the sources reject on their own grounds. On diatomaceous earth, Texas A&M states that “when applied as a dust or drench to fire ant mounds, diatomaceous earth usually does not eliminate colonies.” On soap products, it states that “these insecticidal products are not registered to treat fire ant mounds” and that the manufacturers do not support uses outside their directions.

And Clemson’s position on the whole category: “Clemson Extension does not endorse or recommend DIY home remedies for fire ant management”.

The Federal Quarantine

There is a federal quarantine, and it is worth knowing what it actually restricts. 7 CFR 301.81 states in full: “No person may move interstate from any quarantined area any regulated article except in accordance with this subpart.”

The list of regulated articles is not in the regulation. 7 CFR 301.81-2 states that “The Administrator has determined that certain articles present a risk of spread of the imported fire ant” and that the list is published on the APHIS website. The list of quarantined areas is delegated the same way. This page therefore does not reproduce either list, because the regulation itself does not contain them.

7 CFR 301.81-4 gives the enforcement power: “Inspectors are authorized to stop any person or means of conveyance moving in interstate commerce they have probable cause to believe is moving regulated articles, and to inspect the articles being moved and the means of conveyance.”

What it does not do is restrict what a householder can buy. The quarantine governs articles moving out of quarantined areas — the kinds of thing that can carry ants. Nothing in the sections read restricts a consumer buying a pesticide, or a pesticide being shipped into a quarantined state.

What This Page Does Not Claim

It does not claim you can clear them. Clemson Extension forecloses that in its own voice: “Notice that the words ‘control’ and ‘manage’ are used when referring to fire ants, and no form of the word ‘eradicate’ will appear here. The biology of fire ants and the constant reinfestation pressure from outside areas do not allow for complete eradication.” UF/IFAS Extension agrees: “no fire ant control method (with possibly the exception of biological control agents) will permanently eliminate ants from an area. Fire ants can quickly re-infest areas after treatment stops”.

The label decides what is legal and where. Clemson Extension states: “It is a violation of Federal Law to use a pesticide in a manner inconsistent with its label and labeling.” AgriLife Extension states that the label determines where a product can be used — lawn, garden, agricultural production pasture or orchard — and that users should read it to be sure the site they are treating is listed. NC State Extension adds that some products are not labeled for edible plants.

What to do with what is left over, from Texas A&M and AgriLife Extension, near-identically: do not leave insecticide granules on streets or sidewalks after application, because they wash into storm sewers; follow label directions when disposing of pesticides and containers; and never pour leftovers down the drain.

And where this stops being a job for a householder. Texas A&M states: “If you and your neighbors prefer not to apply pesticides yourselves, or want to ensure that treatments are applied uniformly and on time, consider a professional pest control company.”

One note on what “organic” means here. Texas A&M is careful about it: the organic certification programmes “are solely for certified organic food and livestock production. There is no similar program that applies to nonagricultural pest management practices where options termed ‘organic’ may be based on personal judgment and disputed by others”. That is why the only organic criterion used on this page is an OMRI listing, which is a certification a reader can check.

Questions

Sources

Every factual claim above names the source it rests on, in the sentence that makes it or in the text immediately adjacent to it, and every source named is listed below. Where two sources disagree, both are given with the source that holds each position rather than one being chosen. The wording, ordering and emphasis are our own judgement and are not a finding of any source. The products named on this page were read from their own listings on 25 August 2026 and are recorded rather than assessed; the listings read were B00GRT5E18, B08YS87GR5, B015BSWVCU, B0DV9W259K, B08MB5VG9M, B072KL69L5, B0FDH2LTTN and B007VR5H3K, each reachable from its own card above where the disclosure sits directly beside the link. No claim is made anywhere on this page about whether any of them can be bought today, and no price appears anywhere on it.

1. Texas A&M / Texas Cooperative Extension (Michael Merchant and Bastiaan M. Drees). The Texas Two-step Method (L-5070) — the source of the equipment, rain, freshness and activity-test criteria. August 2003. https://williamson.agrilife.org/files/2014/08/two-step-L5070.pdf
2. Texas A&M AgriLife Extension (Wizzie Brown). Natural, Organic, and Alternative Methods for Imported Fire Ant Management (ENTO-009) — the source of the home-remedy evaluations and the native-ant threshold. March 2014. https://research.entomology.tamu.edu/wp-content/uploads/sites/28/2014/03/ENTO_009.pdf
3. Texas A&M (Bastiaan M. Drees). Medical Problems and Treatment Considerations for the Red Imported Fire Ant (Fire Ant Plan Fact Sheet #023) — the source of all sting material on this page. December 2002 revision. https://research.entomology.tamu.edu/wp-content/uploads/sites/28/2011/12/FAPFS023_2002rev_Medical.pdf
4. Texas Imported Fire Ant Research and Management Project, Texas A&M. Two-Step Method (programme page). Accessed 25 August 2026. https://fireant.tamu.edu/controlmethods/twostep/
5. AgriLife Today (Paul Schattenberg, quoting Robert Puckett, Ph.D.). Spring is the time for Texans to 'two-step' toward fire ant control — the source of the label-is-the-law and environmental instructions. 20 March 2024. https://agrilifetoday.tamu.edu/2024/03/20/spring-is-the-time-for-texans-to-two-step-toward-fire-ant-control-2/
6. AgriLife Today (Adam Russell, quoting Robert Puckett, Ph.D.). How to get rid of fire ants: Expert tips that work — the source of the current rate, rain and placement figures. 10 March 2026. https://agrilifetoday.tamu.edu/2026/03/10/how-to-get-rid-of-fire-ants-expert-tips-that-work/
7. UF/IFAS Extension, Solutions for Your Life. Sustainable Fire Ant Control — the source of the native-ant warning, the liquid-feeding mechanism and the hot-water figures. Accessed 25 August 2026. https://sfyl.ifas.ufl.edu/lawn-and-garden/sustainable-fire-ant-control/
8. Clemson Cooperative Extension, Home & Garden Information Center. Hints and Tips for an Effective Fire Ant Management Program in Home Landscapes Using Broadcast Baits — the source of the spreader exclusions, the season dates and the eradication sentence. Accessed 25 August 2026. https://hgic.clemson.edu/factsheet/hints-and-tips-for-an-effective-fire-ant-management-program-in-home-landscapes-using-broadcast-baits/
9. NC State Extension / TurfFiles. Fire Ants in Commercial Turfgrass, Home Lawns and Landscapes — the source of the two-bumps character, the water volume and the shelf-life figure. Accessed 25 August 2026. https://content.ces.ncsu.edu/fire-ants-in-turf
10. N.C. Cooperative Extension, Pamlico County Center (Teresa Casey). Fire Ants (Solenopsis Invicta) — Insect Note, the source of the size range and the mound description. 19 September 2025. https://pamlico.ces.ncsu.edu/news/fire-ants-insect-note/
11. Office of the Federal Register / APHIS. 7 CFR 301.81-1 Definitions — the source of the federal definition of the term. Title 7 current as of 21 August 2026. https://www.ecfr.gov/current/title-7/section-301.81-1
12. Office of the Federal Register / APHIS. 7 CFR 301.81 Restrictions on interstate movement of regulated articles. Title 7 current as of 21 August 2026. https://www.ecfr.gov/current/title-7/section-301.81
13. Office of the Federal Register / APHIS. 7 CFR 301.81-2 Regulated articles. 87 FR 80012, 29 December 2022. https://www.ecfr.gov/current/title-7/section-301.81-2
14. Office of the Federal Register / APHIS. 7 CFR 301.81-3 Quarantined areas. Title 7 current as of 21 August 2026. https://www.ecfr.gov/current/title-7/section-301.81-3
15. Office of the Federal Register / APHIS. 7 CFR 301.81-4 Interstate movement of regulated articles from quarantined areas. Title 7 current as of 21 August 2026. https://www.ecfr.gov/current/title-7/section-301.81-4
16. Office of the Federal Register / APHIS. 7 CFR 301.81-5 Issuance of a certificate or limited permit. Title 7 current as of 21 August 2026. https://www.ecfr.gov/current/title-7/section-301.81-5