If you live in Texas, you already know: fire ants are everywhere. The red imported fire ant (Solenopsis invicta) arrived in the United States through the Port of Mobile, Alabama, in the 1930s and spread across every county in Texas by the 1990s. Today, there are an estimated 20 to 40 mounds per acre on untreated residential land in DFW, Austin, San Antonio, and East Texas.

Fire ants are more than a nuisance. Their stings send roughly 14 million Americans to the medicine cabinet every year and cause fatal anaphylaxis in a small number of hypersensitive individuals. They damage electrical equipment, undermine driveways and foundations, and kill ground-nesting wildlife. The Texas A&M AgriLife Extension estimates fire ants cost Texans more than $1.2 billion annually in medical treatment, property damage, and agricultural loss.

This guide was written by licensed pest control technicians who treat fire ant infestations across Texas every week. We will walk you through every proven elimination method—what actually works, what is a waste of your Saturday, and when it makes sense to call a professional.

What Are Red Imported Fire Ants?

Red imported fire ants (RIFAs) are small, aggressive, reddish-brown ants between 1/16 and 1/4 inch long. A single colony can contain 200,000 to 500,000 workers and one or more egg-laying queens. Colonies with multiple queens—called polygyne colonies—are increasingly common in Texas and are significantly harder to eliminate because the workers freely move between interconnected mounds.

Fire ants build distinctive dome-shaped mounds of loose, finely textured soil. Mounds typically range from 6 to 18 inches tall, though in clay-heavy Texas soil they can reach two feet. Unlike many ant species, fire ants do not create a visible entry hole at the top of the mound. Instead, they tunnel laterally and emerge through cracks in the surrounding soil, which is why stepping on or near a mound triggers an immediate swarm.

How to Identify a Fire Ant Mound

• Shape: Dome or irregularly shaped mound of loose, granular soil—no visible entrance hole on top.
• Size: 6 inches to 2 feet tall; can be wider underground than what you see on the surface.
• Location: Sunny areas—lawns, garden beds, along sidewalks and driveways, near A/C units, around foundations, and in electrical boxes.
• Activity test: Gently push a stick into the mound. Fire ants will boil out aggressively within seconds and immediately try to climb the stick and sting.

Fire Ant Bites and Stings: What to Know

Technically, fire ants sting, not bite. They grip your skin with their mandibles (the bite) to anchor themselves, then curl their abdomen and inject venom from a stinger at the tip. Each ant can sting multiple times.

What a Fire Ant Sting Looks Like

1. Immediate: Intense burning sensation and a small red welt.
2. 4–8 hours: The welt develops into a raised, itchy bump.
3. 24 hours: A distinctive white pustule forms at the sting site. This is the hallmark of a fire ant sting and distinguishes it from mosquito bites, flea bites, or other insect stings.
4. 3–7 days: The pustule dries up and the area heals. Avoid popping it—breaking the skin invites secondary infection.

When to Seek Medical Attention

Most fire ant stings resolve on their own. However, seek emergency medical care immediately if you experience:

• Difficulty breathing, swelling of the tongue or throat
• Dizziness, rapid pulse, or a feeling of faintness
• Widespread hives or swelling away from the sting sites
• Nausea, vomiting, or abdominal cramps

These are signs of anaphylaxis—a life-threatening allergic reaction. The CDC estimates about 1% of the population is at risk. If you have had a severe reaction to fire ant stings in the past, carry an epinephrine auto-injector (EpiPen) and inform your household.

First Aid for Fire Ant Stings

1. Brush ants off your skin quickly—they grip tight, so a fast, firm brush works better than trying to pick them off individually.
2. Wash the area with soap and water.
3. Apply a cold compress (ice pack wrapped in a towel) for 15 minutes to reduce swelling.
4. Apply over-the-counter hydrocortisone cream or take an oral antihistamine (like Benadryl) for itching.
5. Do not pop the white pustules. They are sterile and popping them increases infection risk.

The Two-Step Method: Gold Standard for Fire Ant Control

Texas A&M AgriLife Extension and every land-grant university extension service in the Southeast recommends the Two-Step Method as the most effective, cost-efficient approach to fire ant control. It combines a broadcast bait application (Step 1) with individual mound treatments (Step 2) for any colonies that survive.

Step 1: Broadcast Bait Application

Broadcast bait is the foundation of any serious fire ant program. You spread it across your entire yard—not on individual mounds—and let the foraging worker ants carry it back to the colony and feed it to the queen.

How it works: Fire ant bait consists of an insecticide or insect growth regulator dissolved in soybean oil and applied to a corn grit carrier. Worker ants find the grit, carry it underground, and share it through the colony's food-sharing process (trophallaxis). The queen ingests the poison and either dies or becomes sterile, collapsing the colony over days to weeks.

Best products (available at home improvement stores):

• Hydramethylnon baits (e.g., Amdro): Kill the queen within 1–2 weeks. Fast-acting.
• Spinosad baits (e.g., Greenlight, Ferti-Lome): Derived from a naturally occurring soil bacterium. Kills within 2–4 weeks.
• Methoprene / Pyriproxyfen baits (insect growth regulators): Don't kill ants directly—they prevent the queen from producing viable eggs. Slower (6–8 weeks) but very effective long-term.
• Abamectin baits (e.g., Ascend, Clinch): Effective within 2–6 weeks.

Application rules that matter:

• Timing: Apply when ants are actively foraging—ground temperature between 65°F and 90°F. In Texas, that typically means early morning or late evening from March through November. Avoid midday summer heat.
• Fresh bait only: Ants reject stale, rancid soybean oil. If the bait has been open for more than a few months or smells off, replace it.
• Dry conditions: Apply when the ground is dry and no rain is expected for 24 hours. Wet bait decomposes and ants won't pick it up.
• Rate: Follow the label. Most baits call for 1 to 1.5 pounds per acre (about 1 tablespoon per 1,000 sq ft). A hand-held spreader works well for residential lawns.
• Do NOT apply bait directly to mounds. Scatter it across the entire yard. Ants forage up to 100 feet from the mound—they will find it.

Step 2: Individual Mound Treatment (7–10 Days Later)

Wait 7 to 10 days after broadcasting bait, then treat any surviving mounds individually. The delay is critical—it gives the bait time to circulate through the colony and kill or sterilize the queen. Treating mounds too early scatters the workers before they carry enough bait underground.

Effective mound drench options:

• Liquid insecticide drench: Mix a labeled product (bifenthrin, permethrin, or carbaryl) with water per label instructions. Pour 1–2 gallons slowly over and around the mound. The goal is to saturate the entire underground chamber, not just the surface.
• Granular contact insecticide: Sprinkle granules around and on top of the mound, then water them in with a gentle spray from a garden hose.
• Dust treatments: Acephate (Orthene) dust is effective for direct application on mounds.

Frequently Asked Questions

What is the best time of year to treat fire ants in Texas?

The best time to treat fire ants is during the spring and fall when temperatures are moderate, and ants are actively foraging. Avoid the hottest parts of summer and the coldest parts of winter.

Can I treat fire ants myself, or should I hire a professional?

While DIY treatments can be effective for minor infestations, significant or persistent problems may require professional intervention. Professionals have access to more potent treatments and can ensure the entire colony is eradicated.

Are there any natural methods to control fire ants?

Some natural methods, like diatomaceous earth or boiling water, can kill individual ants or small colonies, but they are generally not effective for large infestations. Professional treatments are recommended for comprehensive control.

Did You Know?

Fire ants are not native to the United States. They were accidentally introduced from South America and have since become one of the most aggressive and invasive pest species in the southern U.S.

Professional Tip

Always follow the label instructions on any pesticide product. Misapplication can lead to ineffective treatment or harm to non-target species. For the best results, consider consulting with a pest control professional who can tailor a treatment plan to your specific situation.

Customer Testimonials

"Romex Pest Control helped us eliminate a severe fire ant infestation in our backyard. Their team was professional, knowledgeable, and effective. Highly recommend!" - Sarah J., Austin, TX

"Thanks to Romex, our property is now fire ant-free. The Two-Step Method they used was thorough and efficient." - Mike R., Dallas, TX

Case Studies

Case Study: Residential Property in Houston, TX

A homeowner in Houston was experiencing frequent fire ant infestations despite regular DIY treatments. Romex Pest Control conducted a thorough assessment and implemented the Two-Step Method. Within weeks, the infestation was controlled, and the homeowner reported no further issues.