Fire ants are one of the most treacherous lawn pests, inflicting painful stings on people and pets unlucky enough to wander into their path and also creating massive mounds that damage lawns and plants. Luckily, there are a variety of chemical and natural solutions that work well against them.
You can get rid of fire ants with natural remedies like boiling water, diatomaceous earth, or soapy water or go the chemical route with ant baits or direct contact formulas.
How to spot fire ants
Fire ants can be tricky to spot at first, but once you know what to look for, they’re easy to identify. Here are some helpful tips:
What they look like
Fire ants are small but fierce. These reddish-brown insects range in size from ⅛ to 1/4 inch and feature a smooth, shiny body with standout antennae. If you look closely, you’ll see a stinger at the end of their abdomen – the reason their bites are so painful.
Their nests are dome-like mounds of dirt with no clear opening on top. Instead, fire ants enter and exit through tiny holes near the base. You’ll usually find these mounds in flat, sunny areas and near water sources, reaching up to 2 feet high if left undisturbed.
Behavior
Fire ants come in different species, but the South American red imported fire ant is the most common and problematic in the U.S. Its ability to outcompete native fire ants makes it the leading fire ant pest in most areas.
These insects gather in warm, sunny spots like lawns, gardens, and open fields between spring and fall because they like temperatures between 70°F and 90°F and prefer foraging in the early morning and late afternoon. While cold slows them down, they don’t go completely dormant. On warmer winter days, they can continue foraging.
When their nest is threatened, fire ants swarm and attack in large numbers, delivering sting after burning sting that can cause allergic reactions.
The damage they cause to your lawn
Alabama Extension | Flickr | Public Domain
Some telltale signs of fire ant damage to your lawn include:
- Mounds: Fire ants tend to split off from their colonies and start new ones, so your lawn can end up dotted with mounds. This creates a patchy, uneven look. Mounds also create bumps in the grass, making it tough to mow your lawn or walk across it.
- Root damage: Fire ants often tunnel near or under plant roots for food. Their digging can dislodge plant roots, affecting the health and stability of your grass and other plants. This stress can make your lawn susceptible to diseases, other pests, and drought.
- Uneven water drainage: Fire ants create tunnels that can change how water flows through your lawn. If the soil becomes too loose, water can drain unevenly, not even reaching certain parts of your turf.
- Soil erosion: When fire ants dig, they create weak spots in your lawn that are more open to erosion – especially during heavy rainfall.
How to get rid of fire ants with pesticides
The most effective way to eradicate fire ants is through a two-step process that treats the entire yard and also attacks individual ant mounds as they appear.
Once or twice a year, apply a broadcast bait product across your entire yard. In between broadcast treatments, tackle individual active mounds with specialized mound treatments, experts at the Texas A&M AgriLife Extension say. Think of it as a one-two punch for fire ants.
Broadcast bait treatments
Broadcast baits contain a slow-acting pesticide that worker ants carry back to their mound and share with the colony. Over time, this kills the queen and the rest of the ants, effectively wiping out the colony.
Choose a broadcast bait specifically designed for fire ants, as not all baits work the same. Apply it on a dry day when the ground isn’t wet and you don’t expect rain for at least 24 hours. Moisture can ruin the bait’s effectiveness, so timing matters. Always follow the instructions on the product label carefully for the best results.
Use a fertilizer spreader to distribute the bait evenly across your entire yard, not just around visible mounds. This targets ants nesting in hidden areas.
Keep children and pets out of the treated area for at least 24 hours to ensure their safety and allow the bait to work undisturbed.
- Where to find fire ant baits: Garden centers, farm supply stores, and online retailers.
- Length of project: About 15 to 30 minutes, depending on your yard size.
- Estimated cost: $15 to $40 per application, depending on the brand and your yard size.
- How long they take to work: Depending on the bait, 1 to 8 weeks.
- When to use them: In late May or early June and then again in late September or early October. Early morning or late afternoon when the insects are actively looking for food.
Individual mound treatments
For stubborn or very active mounds, double down by drenching them with liquid or granular ant killer. Just remember, they only target visible mounds, not new ones forming. That’s why combining bait with mound treatments is your best bet to get rid of fire ants for good.
Liquids: Make a deep hole in the mound with a dowel, broomstick, or any sturdy rod. Next, mix the insecticide exactly as the label directs – precision matters. Pour it down the hole to target the colony, then grab a hand sprayer and apply the insecticide in a wide circle, about 6 to 10 feet out. This extra step helps contain the problem and prevent the ants from spreading.
Granules: Spread the insecticide granules around the mound, about 3 feet out in all directions, following the label’s instructions for the right amount. Then, sprinkle some directly on top of the mound itself. Once everything’s in place, lightly water the area with a sprinkler or watering can. The goal isn’t to soak the mound but to provide just enough water to activate the granules and let the insecticide do its job.
- Where to find contact insecticides: Garden centers, home improvement stores, agriculture supply stores, and online retailers.
- Length of project: Up to 30 minutes, depending on the mound size. If they’re large, you’ll have to monitor them and reapply the treatment.
- Estimated cost: Varies by brand, size, and type of contact killer, but you can pay between $10 and $30 per liquid bottle or granular treatment.
- How long they take to work: 30 minutes to a few hours after application.
- When to use them: Whenever you see active fire ant mounds, ideally in the early morning or late afternoon.
How to get rid of fire ants naturally
Boiling water and natural repellents are effective ways to tackle a fire ant problem without resorting to harsh chemicals. Here’s how to send them packing the eco-friendly way:
Boiling water
Boiling water is one of the simplest and most effective natural fire ant killers. The heat destroys the ants and their nest on contact.
Use a stick or similar tool to make a hole in the center, then slowly pour the boiling water in. Be careful not to let it splash onto nearby grass or plants. Since this method might not get every last ant on the first try, you’ll likely need to do it again for full effectiveness.
Diatomaceous Earth (DE)
Diatomaceous Earth (DE) is a natural, fine powder made from fossilized aquatic diatoms. When you sprinkle it on the mounds, it breaks open the ants’ exoskeletons, dries them out, and kills them.
As long as it’s food-grade, DE is a non-toxic and environmentally friendly red ant killer option. But it won’t wipe out every fire ant, so you’ll need to pair it with other treatments to take down the whole colony. For example, you can combine it with fire ant baits, boiling water, or essential oils.
DE is quite simple to use. First, poke a large hole in the center of the fire ant mound to help the treatment reach deeper into the colony. Next, sprinkle DE directly into the hole, allowing it to coat the tunnels inside. Then, apply another layer of DE over the entire mound and the surrounding area for added coverage.
Since DE stops working when it gets wet, you’ll have to reapply it after it rains or after you water your lawn. Keeping up with reapplications makes sure the ants keep running into the powder, helping to wipe out the colony over time.
- Where to find DE: Most garden centers, online stores, pet stores, and health retailers.
- Length of project: Around 5 to 10 minutes per mound, 30 minutes to an hour for a broadcast application.
- Estimated cost: Around $20 to $50 per bag, depending on the size.
- How long it takes to work: As ants come into contact with it, the full effect may take a few days to a week.
- When to use it: During dry conditions when ants are active, usually in the early morning or evening when the sun isn’t as intense. Wet or damp DE doesn’t work.
- What to use to apply it: A duster or spreader for even application. Specialty sprayers also exist.
Natural fire ant baits
For a more natural approach, you can whip up your own fire ant bait to target the colony. One example is using borax (a type of sodium), sugar, and warm water.
In a small bowl, combine 1 or 1.5 tablespoons of borax with one cup of sugar, stirring the mixture well. Gradually pour in one cup of warm water, stirring constantly until the sugar dissolves completely. This makes a syrupy consistency that is attractive to ants. Optional but useful: add a tablespoon of honey or peanut butter.
Place small spoonfuls of your mixture around fire ant mounds and in areas where you’ve seen the ants. You can also place it in bottle caps or jar lids to help contain the bait and prevent it from spilling over.
The borax is slow-acting, so it won’t kill the ants immediately but will poison the colony over time as they share the bait. This can take up to a week.
My tip: Sugar and baking soda, honey and borax, or essential oils and sugar work just as well. Use a tablespoon of each, stir well, and apply. You can use more, but just remember to keep equal amounts of each ingredient.
Soapy water
Dish soap and water can help suffocate and kill fire ants. The soap immediately starts clogging their breathing pores, leading to their death within minutes of contact. If the colony is young, a generous pour of soapy water may drown most of the ants inside.
To use it to your advantage, mix 1 tablespoon of liquid dish soap or ¼ cup of Castile soap with a quart of water. Add 1 teaspoon of any cooking oil to increase the solution’s effectiveness. Then, make a big hole in the fire ant mound and slowly pour in the soapy water solution.
For ants outside the nest, just fill a spray bottle with the same mix and spray them down. If you’re still seeing ants after a while, just repeat the process as needed.
FAQ about getting rid of fire ants in your yard
Fire ants aren’t just wandering into your yard by chance; they’re after food, water, warmth, and shelter.
They usually can’t resist sugary spills, pet food, or compost. They love warm, sunny areas and often settle into loose or moist soil, mulch, or neglected lawns.
You may not be able to keep fire ants away permanently, but you can make your yard less appealing.
Store food securely, repair leaks, and avoid overwatering. Keep your lawn tidy with regular mowing and dethatching, and use fire ant bait in the spring and fall.
If they enter your home, seal cracks around windows, doors, and the foundation.
Fire ants don’t have natural predators in North America, but it’s a different story in South America. Down there, phorid flies, also called ant-decapitator flies, regularly take fire ants out.
Ant chalk is an insecticide that contains deltamethrin and cypermethrin. While the active ingredients are legal in the United States, ant chalk itself is illegal because it never received the required regulatory approval.
When to call a professional
If dealing with fire ants repeatedly sounds exhausting, you can hire a local pest control pro to get rid of them for good. They have stronger treatments and expert skills to handle fire ants. Remember that one of the best defenses against fire ants is healthy grass. Let a local lawn care pro take care of it so you can take that worry off your plate.
Sources
- “Control fire ants.” Mississippi State University Extension.
- “Fire Ants.” Fort Smith National Historic Site. National Park Service.
- “Fire Ant Frequently Asked Questions.” Texas Imported Fire Ant Research and Management Project. Texas A&M AgriLife Extension
- ”Hints and Tips for an Effective Fire Ant Management Program in Home Landscapes Using Broadcast Baits.” Clemson Cooperative Extension
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Main Photo Credit: Marufish | Flickr | CC BY-SA 2.0
