With so many differences between fire ant killers, choosing the best product for you and your family can be challenging. That's one reason we take time to rate the Best Fire Ant Killers of the Year and simplify the process. With all fire ant killers, it's essential to know the product kills the queen. Because unless the queen dies, the mound continues — even with just six worker ants to help her survive.
All of our top-rated fire ant killers promise to kill the queen — or they wouldn't be top-rated in our mind. While that's the most important factor in killing fire ant colonies, it's not the only consideration. By understanding these criteria for comparing fire ant killers — and how top-rated fire ant killers fit in — you can choose the best fire ant killer for you with confidence.
How Fire Ant Killers Kill Fire Ants
When comparing top-rated fire ant killers, you'll find they work one of two ways: They kill fire ants by contact or they work as bait to attract fire ants that think they're food. Active ingredients vary according to the product, but contact killers generally interfere with the fire ant's nervous system. Bait killers inhibit ant metabolism instead.
With contact killers, fire ants die when they come in contact with the product's active ingredient. This happens when the insecticide touches ants during application or moves through fire ant tunnels. It also occurs as treated ants touch other ants in and around the mound. Contact killers include products such as Over'n Out!® Advanced Fire Ant Killer, our overall pick for best fire ant killer for 2021.
With bait products, the product kills fire ants slowly by design. Ants carry the bait back to their colony to feed other ants, including the queen. Bait's delayed killing action ensures the bait makes it back to the colony's food supply. As fire ants eat, the active ingredient does its work. Some bait ingredients cause ants to stop foraging and feeding. Our top-rated 2021 fire ant yard treatment, Amdro® Kills Fire Ants Yard Treatment Bait, stops fire ant queens from reproducing.
How Fast Fire Ant Killers Work
Contact killers generally work rapidly compared to bait killers. But within each category, individual products vary in how fast they kill fire ants, fire ant mounds and fire ant queens.
Over'n Out!® Advanced Fire Ant Killer Mound Eliminator, our top-rated fire ant mound killer for 2021, is a granulated contact killer that kills fire ant mounds within 15 minutes and kills fire ant queens within 24 hours. Spectracide® Fire Ant Shield™ Mound Destroyer™ Granules, our top 2021 pick for best price, start working immediately to kill ants by contact, killing the queen within a day. A third contact killer in our top-rated list, Ortho® Orthene® Fire Ant Killer1 — our choice for 2021's best value fire ant killer — kills fire ants within 60 minutes.
Bait products act more slowly, but that doesn't mean they're any less effective in killing fire ants and their colonies. Our top-rated bait for 2021, Amdro® Fire Ant Bait granules, have a delayed killing action that kills the queen in about one week. Once the queen dies, any remaining fire ants can't survive, so the colony dies too.
Amdro Kills Fire Ants Yard Treatment Bait, which targets the queen's ability to reproduce, takes longer to work. Foraging worker fire ants only live about five weeks under normal circumstances. With effective baits, it's even less. Without a reproductive queen, the supply of worker ants dwindles, and the fire ant colony starves. Though highly effective, bait products that inhibit reproduction can take several weeks to kill the colony.
How Fire Ant Killers Are Applied
Fire ant killers come in many different forms, from sprays and gels to powders and granules. All the fire ant killers that made our Best of 2021 list are dry powdered or granular contact killers and baits. We like the mess-free convenience these dry products offer. But even though they start dry, some require watering-in after application. The way they're applied varies, too.
Granular products are straightforward to work with, whether you're treating individual fire ant mounds or broadcasting a treatment across your entire yard. Powders can prove trickier because they're more likely to catch a breeze and drift, so always apply on calm days when there's little or no wind.
Instructions for mound treatments like Over'n Out! Advanced Fire Ant Killer Mound Eliminator usually call for sprinkling the recommended rate of the product over the mound and the immediate area around it — usually a circular area with a diameter of about 4 feet. Always follow instructions and measure the product before you apply — don't guess. And always use a disposable measurer or one that's devoted to fire ant killer applications.
For yard treatments, a broadcast spreader like you use for grass seed or fertilizer works best. Granules usually go through the spreader easily, so you can get uniform, consistent coverage in a short time. Amdro Kills Fire Ant Yard Treatment Bait comes in a shaker bag that makes treating smaller areas simple.
One important final consideration is whether the product gets watered-in. Some contact killers, including our 2021 overall winner, Over'n Out! Advanced Fire Ant Killer, must be watered-in immediately after application. Watering-in releases the active ingredients and helps the insecticide solution move down into the mounds and tunnels to contact ants. But not all contact killers require watering; the powdered contact killer Ortho Orthene Fire Ant Killer1 should stay dry.
Bait products must stay dry to retain peak effectiveness and stay attractive to foraging ants. For products like Amdro Fire Ant Bait, don't apply the product if there's heavy rain in the forecast, and don't water after you apply the bait.
How Long Fire Ant Killers Last
Contact killers and bait products vary quite a bit in their active ingredients and how long those ingredients stay effective when exposed to the elements. Some products break down quickly, but others offer residual protection that keeps working and killing ants long after you apply them.
Top-rated contact killers Over'n Out! Advanced Fire Ant Killer and Over'n Out! Advanced Fire Ant Killer Mound Eliminator both contain a long-lasting active ingredient that kills, controls and protects against fire ants for up to six months. That feature can save you time, money and worry when you're unsure when or if fire ant mounds may appear.
But not all contact killers offer that kind of protection. Neither of the other two top-rated contact killers in our 2021 list, Spectracide Fire Ant Shield Mound Destroyer Granules and Ortho Orthene Fire Ant Killer1, promise any long-lasting residual coverage.
The lasting power of bait products can depend a great deal on when you treat and your weather conditions. When you apply bait during times when fire ants are most active, the best baits tend to disappear quickly. Baits can lose their effectiveness when they become wet from rainfall or irrigation. But once fire ants carry the bait away, their underground tunnels can provide protection.
Amdro Fire Ant Bait, for example, retains effectiveness for up to three months after you open the product. Amdro Kills Fire Ants Yard Treatment Bait promises season-long protection, too.
Pets, Children and Fire Ant Killers
For a product to make our top-rated fire ant killer list, we need to feel comfortable that the product can be used in areas frequented by children and pets. When used and stored according to label instructions, none of our best fire ant killer winners put kids or pets at risk.
Following label instructions is essential to protecting your pets and children. As with any pesticide product, clear the area of people and pets before you start. Never apply any product in such a way that it contacts people or pets, directly or by drifting. And never leave any type of fire ant killer in piles, whether it's a contact killer or a bait. Piles can attract kids, pets and wildlife.
Don't ever assume a product can be used around people and pets without precautions. Check the labels or the company website to make sure the product can be used where your kids or pets play. When you've finished your application, including any required watering-in, follow the product's instructions for when people and pets can reenter the treated area.
As a general rule, people and pests can typically reenter watered-in treatment areas once the area dries. For products that don't get watered-in, you may need to wait until the dust settles. Still other products may require you to wait 24 hours or some other set amount of time. But don't forget: You won't find them on our list of top-rated fire ant killers, but some pesticide products shouldn't be used around children or pets at all.
By understanding these key considerations in comparing fire ant killers, you can choose a fire ant killer that meets your family's needs. For more information on managing fire ants, check out our resources on identifying fire ants, avoiding fire ant home remedies and more. Stay tuned for future rounds of fire ant killer comparisons to help you choose the best fire ant killer for you.
The opinions represented in this article are the author's. However, the author has been paid by the owner of this website, Central Garden & Pet Company.