The red imported fire ant has become more than a nuisance for homeowners in Southeastern North Carolina. It seems that every time we, our children, or our pets go outside, that we are at risk for becoming a victim of a dozen or more of these unwanted invaders of our properties. Not only are we at risk outside, but many reports have been made of fire ants moving into storage buildings, under concrete pads, and even into residential homes and commercial properties in our area. Total control of this pest is difficult at best, due to a lack of community wide effort, reproductive life cycle of the ant, and the ants ability to live in areas difficult to treat, such as forests, right of ways, and fields. Our best effort as homeowners, is to try and control the fire ant population on our own properties to minimize contact and avoid the painful stings they deliver.
During the spring and the summer, the ants leave the mound and mate in the air. After mating, the females become queens and can travel as far as 10 miles before landing on the ground and starting a new colony. After mating and finding a suitable landing area, the queen will burrow in the ground and begin to lay eggs. Beginning in late spring and early fall the eggs will hatch, and many more small unnoticeable mounds will appear in your landscape. This is the time when anyone outdoors can receive many bites and wonder where the ants are coming from.
The best way to manage fire ants on your property is to implement a two-step approach of baiting ants with a broadcast bait, followed by individual mound treatments. Both treatments require specific chemicals, and must be used in the correct way to achieve control. Using the right chemical, in the wrong method, will only waste money and time, and does not aid in control.
Baiting may be done near specific mounds, or broadcast across a large area. If you are baiting individual mounds, place the bait in a circle at least 2’ in diameter around the outer edge mound. Not all baits that can be used at a mound may also be used as a broadcast, so make sure you read the label for each application. Baits are actually food and depend upon that food being attractive for the ants to take it in. Some baits are direct poisons and some are insect growth regulators which, instead, cause the colony to die out more gradually. Baits are slower acting than direct mound poisons, so do not expect results overnight. Baits rely on foragers to collect the food and bring it back to the rest of the colony to eat. In mid-morning before baiting, drop one or two potato chips near a mound. If ants are consuming the potato chips at 20 minutes, it is a good time to apply bait.
When purchasing baits, look for active ingredients such as hydramethylnon (Amdro Fire Ant Bait), hydramethylnon+methoprene (Amdro FireStrike baits), spinosad (Come ‘n Get It Fire and Killer, Greenlight Fire Ant Control, Ortho Ecosense) and indoxacarb (Over ‘n Out Mound Treatment, Spectracide Fire And Once ‘n Done). Ensure you are using fresh bait. Baits stored in opened containers or for periods over 1 year, lose their attractant and ants will not consume them. Also, do not store baits near gasoline, oils, or other strong odorous materials as they will permeate the bait and again ants will avoid consuming the bait. Do not apply baits if rain is forecast within 24 hours. Lastly, when baiting, do not disturb the mound. Use the ant’s natural behavior of foraging to your advantage. If you disturb the mound, ants will stop foraging and begin repairs to the damaged mound.
Individual mound treatments should follow baiting in approximately 10-12 days. Directly treating a mound is the fastest method for killing a specific mound. Even so, it is hard to kill every ant and more importantly the queen(s), with certainty. Mounds can be treated directly with insecticide. The insecticide could be powder or granules that are applied atop the mound and then watered into the soil, or they may be dry or liquid insecticides that are mixed with water and then drenched onto the mound. Read the directions carefully for the product you are using. If it is too cold or too hot, ants may not be near the top of the mound. Mid-morning is a good time when temperatures are not too hot nor too cool and mound ants are near the surface. Soil temperatures near 70 degrees F is optimal. Insecticidal mound treatment products should have active ingredients such as z-cypermethirn (Amdro Quick Kill Fire Ant Mound Drench), deltamethrin (Basic Solutions Fire Ant Killer by Ortho), cyfluthrin (Bayer Advanced Powerforce Multi-insect Killer), bifenthrin (Bonide Stinger Fire Ant Killer, Ortho Fire Ant Killer Mound Treatment, Ortho Max Fire Ant Killer Broadcast Granules, Over ‘n Out Fire Ant Killer Granules -broadcast), permethirn (Eliminator Fire Ant Killer Plus!), and deltamethrin (Hi-Yield Imported Fire Ant Control Granules). To achieve the most effective results with mound treatments, read the label thoroughly and mix or drench with the correct amount of water. Treat mounds in mid morning when ants are near the surface of the mound, and disturb the nest as little as possible. Once a disturbance is present, the ants will move the queen to safety and she will continue to lay eggs increasing the ant population.
I would be amiss if i did not address home remedies for fire ant control. The three most common home remedy questions I receive are related to grits, boiling water, and burning ants with gasoline or diesel fuel.
Using grits is a common question I get when dealing with fire ants. Grits have been scientifically proven to not reduce fire ant populations by NCSU. The ants will find and eat the edible parts of the grits and thank you for the snack. There is no significant ant population reductions by using grits as an ant killer.
Pouring boiling water on the mound is another home remedy that I have been asked about. I can only imagine a hundred ways this remedy could end badly, and not for the ants. The safety aspect alone is enough to refrain from using this method, even if you would have a good story to tell 10 years from now about the burn scars on your body.
Pouring gasoline or diesel fuel on the mound and burning is another question I receive. This method not only pollutes your soil and property, but is more dangerous than using boiling water. By the time the first few drops of flammable material hits the mound, the ants go into action and begin moving the queen away from the fumes. She, along with thousands of other ants will relocate to an area not far from the original mound and continue business.
The last strategy for controlling fire ants for the homeowner is to to call a landscape professional and let them do the fighting for you. Landscape professionals have access to higher quality and more potent insecticides to control fire ants than homeowners or gardeners. This access is due to experience, training, certification, and continuing education. Many of these professionals deal with fire ants on a daily basis and can help rid you of your fire ant problem within a few weeks.
More information about red imported fire ants can be found at the following web address: https://www.ces.ncsu.edu/depts/ent/notes/Urban/ifa.htm, or you can call your local extension agent with further questions.