Argentine Ants are one of the most aggressive invasive ants in the world. Discovered in the 1800’s, they can currently be found in approximately 15 countries, as well as some islands and on six continents. In the United States, they are primarily found in Southern California but have also been found in Tennessee, Georgia, Louisiana, Texas, Alabama, Missouri, North Carolina, South Carolina, Arkansas, Illinois, Oregon and Mississippi. Learn how to kill Argentine ants like a pro!
Get Rid of Argentine Ants
Argentine Ant Identification
The Argentine ant is a small, light to dark brown ant about 1/8 inch (2.6mm) in length. They have been reported to crawl onto people and bite them while they are asleep. Reports from the early 1800’s describe babies being attacked in their cribs.
Argentine Ants or Linepithema humile were first identified in 1866 near Buenos Aires, Argentina. All Argentine Ants are a dullish brown color in appearance. They feature an uneven thorax with an erect petiole node directly behind the thorax. These two features are the main identifiers of the Argentine Ant. They also feature segmented antennae which have 12 elbowed segments.
The worker argentine ants do not have wings and are generally lightly spotted. They can be anywhere from 1/12 of an inch to 1/8 of an inch in length. The queen Argentine Ants can be two to four times the length of the workers. Queens may also possess wings too, but won’t swarm when mating like most other species of ants.
Musty Smell When Crushed
In addition to their appearance, Argentine Ants can be identified by the smell they produce when they are crushed. When crushed in large numbers, they will give off a musty smell. Because of this smell, the Argentine ant is most often confused with the odorous house ant.
The node on the abdomen of the Argentine ant has a sharp pointed peak, while the odorous house ant is flat and is hidden. This makes them resemble and can often be confused with Crazy ants and Small Honey ants. The Argentine ant does not have a small circle of hairs on the tip of its abdomen.
Size: 1/8 inch (2.6mm)
Color: light to dark brown
Argentine Ant Workers
Size: 1/8 inch (2.6mm)
Color: light to dark brown
Feeding On Air Freshener
Horned Lizard Decline
While Argentine Ants are tolerant of each other, they are still very aggressive in nature towards other species of ants and insects. When colonies of these ants move in to an area, they will kill and run off the other ant species and claim the area for themselves. This tendency has caused a major problem for the horned lizards in Southern California.
Horned lizards depend on harvester ants for food. However, when Argentine Ants move into the area, they begin to eliminate harvester ants by taking away their food source and fighting them off. The elimination of these food sources is detrimental not only for harvester ants, but also for horned lizards and contributes to the horned lizards decrease in population in some areas of the United States.
The other contributing factor is that Argentine Ants have been known to attack horned lizards if they living in the same area. These ants have also been known to successfully attack killer bees and wasp nests.
Super Colonies – Millions of Argentine Ants
Argentine Ants are unique for a number of reasons, but one of the most unique characteristics about them is the fact that they are tolerant of other Argentine Ant colonies nearby. The way these “Super Colonies” are formed is when a single colony gets too large. The Queen ants will mate inside the nest and then leave the nest with a group of worker ants and start a new colony.
These colonies have been known to be very close to others, they will even share workers at times. And, if needed, the individual colonies will team up with one another to attack enemies.
In southern California, one study found a trail of Argentine Ants over 30 miles long. It is thought that the individual colonies of Argentine Ants over this area formed into 1 super colony. The number of ants in this super colony could be over well over 1 billion.
Over 15 Queens Per 1,000 Workers
In Argentine Ant colonies, there is usually more than one Queen ant. In fact, for every 1,000 workers, there can be up to fifteen (15) Queens. These Queen ants will mate with the males to populate the colony. This is the sole purpose of the male ants – to mate.
The eggs the Queens lay are usually those of sterile female worker ants. The sterile female workers have a variety of responsibilities that include nursing eggs, foraging for food, feeding the larvae and even tending aphids for their honeydew secretions.
Argentine ants have multiple queen colonies and the queens will often be found along argentine ant trails. Occasionally, winged queens will be seen in a colony. These queens can live about a year. A typical colony consists of about 90% workers and 10% Queens.
The Argentine ant is a nuisance because it is ideally suited to urban environments. Where it occurs, it can be one of the most invasive and difficult pest ants to control.
Argentine Ant colonies are “unicolonial” (K. Kupfer – KM Ant Pro). A single colony of Argentine ants can contain thousands of workers and hundreds of queens. These colonies often intertwine and connect with each other, this is what makes control so difficult.
Argentine Ant Control Strategies
Many Argentine Ant control strategies have been developed over the years. Everything from sprays to baits and traps have been marketed for their control. Almost nothing has worked with the exception of certain liquid baits and non-repellent insecticide sprays such as Termidor. All over-the-counter insecticide sprays are repellent, and are useless in Argentine Ant control.
Why Insecticide Sprays Don’t Work
As mentioned, hardware store variety insecticide sprays that are available for Argentine ant control are all repellent. Only those products containing Fipronil or Imidacloprid such as Termidor and Premise have shown any results. These products are professional use and have strict limitations on where and how they are used. They cannot be used around gardens or food crops.
With Fipronyl, in most States, a single perimeter application of a “band” around the outside of structures every 6 months is all that is allowed. Fipronil is not labeled for indoor spraying – only exterior perimeter use. This hardly results in long term control of Argentine Ants.
Imidacloprid can be used on lawns, but does not render the same results as fipronil. Overall, you can expect the ants to reappear in a short period of time when using either of these products.
Killing the exposed worker ants and establishing a repellent barrier only makes them worse. In most cases, over-the-counter sprays make Argentine Ants worse by “alarming” them and causing an increase in reproduction, egg laying and colony “budding”.
A single Argentine Ant colony exposed to repellent insecticide sprays such as those containing permethrin, bifenthrin and others can “bud” and multiply into several new colonies in a short period of time.
“Do not spray any repellent spray pesticides around Argentine Ants. Spraying will not kill the queens and will increase egg laying. This will compound the problem and make it many times worse.”
When you are dealing with millions of ants over a wide area and the potential for “super colonies”, spraying them may seem tempting but in the long run will make them worse. It almost always results in making their populations grow. Don’t be mislead by fancy packaging and misleading advertising claims. There are no quick cures for Argentine Ant control.
The best advice for getting rid of and controlling Argentine Ants long term is to use a strategic method of liquid baiting. This is what most University Studies recommend. As a homeowner or property owner, it is the only means by which you can expect to gain control.
Use Slow Acting Liquid Baits
Long term control of Argentine ants can only be achieved with acting liquid baits. Not granular baits, not insecticide granules, but liquid baits containing boron based boric acid. Slow acting liquid baits ensure that the workers have time to return to the colony with the “toxicant” and distribute it.
The only products that have resulted in long term control of Argentine Ants is the KM Ant Pro liquid bait dispenser and Greenway Liquid Ant Bait. This is an outdoor baiting system that provides the ants with a constant food source. It also kills the workers slow enough to not “alarm” them or cause any disruption.
This combination has proved the most beneficial in University and Government funded studies. It is also used in National Parks, by major growers and in countries around the World.
This will also kill the colony from within, including the Queen ants. Most pesticide sprays only kill the worker ants and will not penetrate the core of the colony. Additionally, when using sprays you may actually stress out the colony which can cause the Queens to lay more eggs for colony preservation. The colonies will then split or “bud” into several new colonies. This is called ant colony “budding”.
Argentine Ants need a damp environment or some water source for survival. They must also be close to a reliable food source. Argentine Ants love sweet foods such as Citrus juices and honeydew, but will also eat almost anything that is insect, plant or animal related.
As these ants forage for food, they leave “pheromone” trails behind to ensure that they don’t make unnecessary visits to areas they’ve already cleared of food. However, they also leave “pheromone” trails which instruct the worker ants to feed.
Argentine ants are an outdoor pest. They thrive outdoors. In some environments including crop fields and orchards, they are a tremendous problem and can cost millions of dollars in damaged products. Insecticide spraying in these settings just doesn’t work.
Outdoor baiting with the KM Ant Pro Liquid Bait Dispenser and Greenway Liquid Ant Bait is the most effective. This combination has been under evaluation by the USDA, several Universities as well as many Vineyards in the California NAPA Valley. It provides the best long term control of argentine ants for the least amount of expense and also zero environmental impact.
The reason outdoor baiting is highly recommended and preferred, is due to the enormous populations that some Argentine ant colonies maintain. Millions of Argentine ants covering acres of land, neighborhoods, parks, etc can’t be controlled by using pesticide sprays.
Slow acting baits that are available to Argentine ants 24 hours a day for months without interruption has proven to be the only way to control them.
The KM Ant Pro liquid bait dispenser provides an alternative food source containing a honey and boron based bait matrix. This combination provides them with a food source that is slow acting enough to kill the worker ants over a 60-90 day period. Slow enough that the colony does not get disturbed or stressed and begins repopulation and egg laying efforts.
Related: KM Ant Pro Liquid Bait System
Once the worker ants have died, the colony cannot feed itself and begins to slowly starve. Over a period of several months, 90%+ control has been obtained in areas where pesticides provided little to no control.
The KM Ant Pro system will kill outside foraging ants preventing them from getting indoors, and also create a protective barrier that stops off-premise ants. It works for almost all species of invasive aggressive ants and is especially suited for the Argentine ant.
Indoor treatment for Argentine ants begins outdoors. Unless the outdoor invading ants are stopped, they will continually invade and indoor control efforts of any kind will be useless.
Argentine ants feed on plant juices, honeydew, and insects, etc. In most cases, even when infesting indoors, they will travel outdoors for these food sources. This is why indoor baiting does not have the same effect as outdoor baiting. Outdoor baiting kills indoor ants that are collecting food sources.
Indoor baiting will have little to no effect on a large ant colony.
Treatment of wall voids with BorActin Dust can give limited results, although it usually takes several weeks to months to get control. Repeated applications may also be necessary to “dust” areas where ants are seen or found.
Indoor baiting with or Advion Ant Gel can also effective. No indoor treatment is 100% effective, because Argentine Ants live and forage primarily outdoors.
Unless you treat outdoors continually, with a long term outdoor spray program (not recommended), you will have to use a baiting system such as the KM Ant Pro Ant Liquid Bait Dispenser and Greenway Liquid Ant Bait.
This system provides 24/7 feeding for Argentine ants and is used by hundreds of thousands of homeowners as well as numerous Citrus growers, farmers and agricultural companies all across the Southern Coast States.
Given time this system will control indoor ants, and also provide a natural food source for future invading ants. Don’t worry, the KM Ant Pro System won’t attract Argentine Ants, but it does provide a food source for existing ants.