The Argentine Ant

Argentine ants are not native to the United States but were brought here in the 1890’s and are considered a serious invading home invading pest. This small brown ant (2-3 mm in length) looks very similar to other ants but its habits of area and specie domination have put in the top 100 list of most invasive insect. Argentine ants do not tolerate other species of ants which can throw the balance off of an area and other creatures also suffer with their presence. Lizards in California for example that depend on other ants for food have declined in population with the take over of this dominate pest. Normally brown in color, shiny and almost completely hairless this non de-script ant is best identified by its behavior.

Argentine ants will nest almost anywhere. Under cement slabs, wood piles or debris, potted plants and even underground. The nest site changes quite often with the availability of food and water. The colony will have many queens but they rarely swarm preferring to mate inside the nest. They do not sting but can and will bite. This aggressive ant drives out other ant competition and will even devour whole termite or bee colonies.

The argentine ant readily enters our homes through very tiny cracks or gaps. This efficient ant lays down scent trails not only from the nest to a food source but also to areas that have been explored before. Thousands descend on found food sources but are mainly attracted inside your home for water. This ant is fond of sweets but will readily make a meal out of other insects, meats, garden and other organic matter. Their shear numbers often out pace pest control efforts and professional help is recommended.

How They Move

This ant was believed to be brought to America in coffee ships from Brazil to New Orleans and still travels much the same today. It is often found as a stow away in trucks, moving vans or shipments. Colonies can easily reach the million or more range and this allows them to dominate their territory. DNA in the argentine ant is also unique in that separate colonies have ‘merged’ because the ants recognize other argentine ants and they mingle, co-habit and spread together. This ability has made way for “super colonies” that can stretch for thousands of miles.

How Best To Identify Argentine Ants

Since this ant has no readily visible markings you may need to have a professional ID this specie of ant. It is a very small ant about 2 to 3 mm and is shiny brown to black in color. It is noted for it’s endless single line of foragers and huge numbers that swarm a food source and once an area is cleared they rarely visit it twice. There are no soldiers ants in the colony and all argentine ants are the same size.


Argentine ants are heaviest in wet areas and are mostly confined to coastal states but have spread out to invade near by areas. From California to Florida and as far up as the Carolinas this ant has been reported. Colonies have also been found in Washington State near Puget Sound and even Illinois.

Treatment And Elimination

It is for the most part impossible to eliminate this ant due to its huge numbers and ‘super colony’ effect. Keeping them out of your home can be achieved but returning ants is always possible. Pest proofing is always helpful but difficult to seal all the tiny cracks, gaps and voids these ants can use. Caulk or seal as much as possible. Reducing water sources is a main key to deter this ant. Rerouting a/c lines away from the home, stopping leaky spigots and keeping pet dishes elevated is helpful. Finding nest sites and destroying the ants is an excellent way to relieve ant ‘pressure’ from around a home.

Exterior liquid treatments with Bifen IT works well around windows, doors, entry points and the base of the home. Granule barriers with Talstar also provide some protection. Interior sprays using Suspend SC or Demand are good to repel ants as well as dusts in voids using Borid, DE (diamataceous earth), Delta or Drione. Ant baits such as Advion gel or Terro placed in cracks, crevices or pathways will also work.

About The Bug Doctor

Jerry Schappert is a certified pest control operator and Associate Certified Entomologist with over two and a half decades of experience from birds to termites and everything in between. He started as a route technician and worked his way up to commercial/national accounts representative. Always learning in his craft he is familiar with rural pest services and big city control techniques. Jerry has owned and operated a successful pest control company since 1993 in Ocala,Florida. While his knowledge and practical application has benefitted his community Jerry wanted to impart his wisdom on a broader scale to help many more. was born from that idea in 2007 and has been well received. It is the goal of this site to inform you with his keen insights and safely guide you through your pest control treatment needs.

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  • I might be mistaken, but I have not seen this type of ants in Texas. They seem like a nightmare.

  • Luay,

    I’m not sure how far they extend in your state or how the heck they got up to Washington even but in my research I found these reports right from Texas A&M website (among other sources)

    I’ve not been aware of them here in Florida either but some of my contacts say they’ve had run in’s with em. Personally- I’ll be happy if they don’t come our way. You’re right they do seem like a handful.

  • Keith

    If I recall the Jacksonville Zoo has been dealing with Raspberry Crazy ants and they are quite impressive. California has them everyone in the south I think as well. The problem are the offspring don’t fight with neighboring sisters and take out native species. Good info

  • Thanks Keith,
    Yep I remember your article and pics of the zoo
    So I’m about 2 hours from Jacksonville who has major problems and the same from Tampa that I know also has em–Since I’m in the middle all I can think is the ants either skipped us or are getting ready for an all out assault from both sides……… can I borrow some equipment… 😉

  • Mel

    I’m always fascinated with the distribution of insects and how well they adapt to new environments. As for how they got up to Washington State, Im guessing transported by 20 plus years of Californians moving up here combined coastal moderate weather allowing them to thrive.

  • I had forgot that Washington was sort of a ‘tweener’ state for Californians to escape to. I’m sure some even brought their hybrid eh em–medicinal plants. 😉

  • Valhalla62

    I have always thought that Argentinian ants would fight with the red carpenter ants. But that appears to not be the case, at least here in Flagstaff AZ. I have a nest of each about 20 inches apart in my backyard and they don’t look like they are fighting at all. The 2 nest popped up about 10 days ago and the red ants are freely moving about the black ants nest. I even saw a red ant go down into the black ants hole, I thought he was a goner, but he crawled back out 20 seconds later. The black ants will crawl over the red ants but then the red ants just continue on there business. After 10 days it appears that the black ants numbers are less, and the red ants are about the same. I wasn’t sure if this is common or not, just thought it was interesting

  • Super interesting… We have fire ants here that fight with others some but ‘pavement ants’ are the most territorial I’ve seen…. They get in all out brawls on sidewalks and driveways sometimes….Thanks for taking time to comment and feel free to let us know how it develops.

  • Valhalla62

    Sorry I said carpenter ants and I meant harvester ants

  • Harvester ants just look nasty! They do hew out a nice patch of grass (weeds and all) for their entry–bout the size of a basketball. And they are hard to kill even when dousing the nest… I can imagine they’d be able to reduce some ant numbers with those big ol pinchers!!