I was working in the yard this past weekend, finally getting to a few of those clean-up projects I had been putting off like removing the Virginia creeper (Parthenocissus quinquefolia) and trumpet creeper (Campsis radicans) from my azaleas (Rhododendron spp.). As such, I was in an area of my yard that doesn’t see the mower frequently when I ran into my arch nemesis of the summer season…fire ants. I recall the very first time I got eaten up by fire ants as a kid, I was in Florida visiting my Aunt Shelly. She lived on the edge of a swamp and so I was helping my cousins to clean up the shoreline so we could see the alligators. First, it was one of my older cousins who was howling and we all began to laugh. Then they got to me and it was no laughing matter! I ran directly to the pool and jumped in with my long pants and boots! Undeterred by the cool water for what seemed like an eternity, they continued to bite until I got those clothes off in the pool! Here we are and now I’m old enough to know better but still getting bit by these little jokers. The bad part is that I don’t have a pool to jump into!

During these seasons when we are warm and dry, fire ants can be prolific! So, what can you do in your yard? The first line of defense is always cultural control, that is to say, management activities that we can control. We come into contact with fire ants, like many undesirable pests, while they are foraging. We can mitigate the abundance of fire ants by controlling the amount of forage we leave behind! Outdoor trash cans around our homes, public places, and even schools should be emptied frequently during the day. Make an effort not to leave cans with trash, especially food, overnight. Keep the area around the trash cans clean. Clean any spillage immediately. Trim shrubs around your home or office to keep the ants from using them as a bridge to get across treated areas. Mowing your lawn frequently, and at the right height, has been shown to deter fire ant establishment in turf.

Next, there are chemical treatments. There are baits, mound drenches, and broadcast insecticides available. Individual mound treatment is always the best to ensure off-target species are not killed. Always remember that beneficial insects can be killed too. When we kill beneficial insects, we usually create a bigger problem than we started with.

Fire ant mound with bait places around the mound. Photo by Gene Fox

The best course of action is a two-step method, using both baits and mound drenches to treat individual mounds. In this method, baits are placed around the mound, foragers carry the bait back to the mound, and begin to kill the queen and larvae. Two to three applications, spaced 5-7 days apart, will provide great results. A word about baits, they are just that, bait! If you allow it to sit out in the hot sun before application, it is going to lose much of its appeal to the ants. Keep baits closed up tight, out of the sun, and out of reach of children. Next, use a mound drench to finish off the colony. This is done according to application directions on the product label. You will need to mix the chemical as directed and then water it into the mound with the correct amount of water. When adding the water to the mound, it is best done with a shower head or sprinkler can. Be sure to wear proper personal protective equipment (PPE) when applying any chemical! The idea here is to resemble a rain event such that the mound isn’t disturbed. This is best done early in the morning so that the ants aren’t out foraging yet.

Lastly, there are broadcast applications of insecticides. These are really good as a maintenance application or if you have widespread activity and are trying to get a handle on the population. Broadcast applications work best when we get closer to the fall but will work well now if you have an issue. Soil temperatures tend to be warmer and in most years it is drier towards August and September. This is when the ants are most active and open to treatment. Several products are marketed for treatment. Look for the active ingredients acephate, bifenthrin, or carbaryl. There is another that requires a pesticide license with the active ingredient fipronil. This is the same ingredient found in products used for flea control on our dogs. This product is more expensive but will work against the ants for a full 12 months!

For more information and examples of products that can be used to treat fire ants around your home or business, visit the NC State publication on Red Imported Fire Ant in North Carolina, Biting and Stinging pests. NC State Extension provides unbiased, research-based, University information to you the consumer or producer. If you have not visited your local Cooperative Extension Center, you may be pleasantly surprised by all of the information, workshops, and programming we offer!

If you have a question to submit, please email to Gene Fox at gene_fox@ncsu.edu. Having trouble with growing in your home landscape, call the Extension office and speak to an Extension Master Gardener^SM Volunteer (EMGV’s), Mondays and Wednesdays between 10:00 and 12:00 at (252)946-0111.