What You Should Know About Argentine Ants (and How to Get Rid of Them!)
Argentine ants (Linepithema humile) are incredibly prolific breeders and an invasive ant species that boasts very large colonies. They are also very aggressive. They continuously attack other ant species with their large numbers, often joining forces with other Argentine ant colonies, to wipe out other ant colonies.
Argentine ants are originally native to South America, primarily in Argentina, Uruguay, Paraguay, Bolivia and southern Brazil, but can now be found in many places throughout the world, including the United States, Japan, Europe, South Africa, Australia, and New Zealand.
How Do You Identify Argentine Ants?
Argentine ant workers usually range in color from light to dark brown to black, and are about 1/8" to 3/8" in length. They are segmented and oval in shape, do not have wings, and their antennae have 12 segments (and they produce a musty odor when crushed, unlike most other ant species that put off an acidic smell). Argentine ants are distinguishable by their mandible (jaw/mouthparts) with 5-8 large teeth, and their smooth and hairless bodies. Queen Argentine ants are a bit larger than workers, and are usually about 1/4" in length. Queens and reproductive males may have wings.
Like other ant species, Argentine ants go through a full metamorphosis (egg, larva, pupa, and adult). Temperature will affect their development (lower temps slow them down), but these ants can go from eggs (hatching in about 28 days) to full adulthood in about 105 days.
Argentine ant colonies have been known to house hundreds of queens, millions of ants, and can cover entire city blocks.
Do Argentine Ants Bite?
Argentine ants do not have stingers and only bite humans when they are provoked or threatened. Their bites are harmless, however, and not a health risk to humans.
Are Argentine Ants Harmful to Humans?
Argentine ants pose no significant health risk or threat for humans, but they do crawl all over everything, including trash, sewage, animal carcasses, etc., and can quickly and easily transport bacteria wherever they go, including all over your food if they get into your kitchen. Argentine ants have also been known to attack beehives and poultry chicks.
Where Do You Find Argentine Ants?
In the U.S., Argentine ants are known for occupying several of the southern states, as well as California and Hawaii. Fewer numbers of them might also be found in Maryland, Indiana, Illinois, Missouri, Arizona, as well as in the Pacific Northwest.
Argentine ant colonies are most often housed in damp environments, relatively close to a food source. Outside, these ants will build shallow nests in damp/wet locations like underneath boards, plants, and rocks, and along sidewalks.
Whenever conditions are less than ideal for Argentine ants to survive (lower temperatures and less moisture), they will readily head indoors, and usually in large numbers. Indoors, they will regroup near sources of moisture (e.g., water pipes, sinks, potted plants, etc.).Often they will get into your home via tree branches, shrub branches, and utility lines that make contact with the structure.
How Did Argentine Ants Get Into My Home?
Argentine ants are very invasive, very numerous, and very difficult to control. They will readily attack the colonies of other ant species, attempting to displace them and take over their colonies. This can be harmful to the local ecosystem, as some ants are important to the health of some plants and other creatures. Did we mention they are a pain to get rid of?
Moist areas such as mulch, underneath yard debris, underneath piles of lawn litter, and home foundations are all appealing to Argentine ants. As summer ends and the weather cools down, these ants will move out of these outdoor living spaces and try to get into your home through gaps and cracks around the foundation to find shelter. Indoors they often nest in wall and floor voids.
Do I Have an Infestation of Argentine Ants?
The most telltale sign of an Argentine ant infestation is seeing trails of them (remember, there are a lot of them in their colonies!), usually traveling up buildings and trees (and trying to get into your home). Their trails are often wide, and very noticeable.
How Do You Get Rid of Argentine Ants?
The best long-term and reliable way to eliminate Argentine ants is to use a good ant bait. Maggie's Farm No Spill Ant Kill bait stations can wipe out an entire colony of ants. When properly used, No Spill Ant Kill bait stations and Maggie's Farm Ant Killer gel bait will wipe out the colony, without the mess of other liquid baits. Foraging worker ants find the bait stations or bait droplets you've put out for them, then will go back and share it with the rest of the colony. Because Argentine ant colonies can be very large, the more bait used the better. And be prepared to replace empty bait stations and adding more bait droplets as these foraging ants take all the bait. As long as the ants keep taking the bait, it is working as it should. It will just take longer to wipe out very large colonies. Both solutions work well indoors and outdoors.
Sprays can be used indoors and outdoors, work well as a spot treatment for ants you see, and they also work well on an Argentine ant nest, if it is exposed. Maggie's Farm Ant & Roach Killer spray not only kills Argentine ants, it also kills other species of ants (including Carpenter ants), bed bugs, cockroaches, spiders, ticks, fleas, and a variety of other crawling pests. You can also use Maggie’s Farm Home Bug Spray as well. It will also kill ants, including Argentine ants, along with many other crawling insects.
You can also use an outdoor perimeter spray to establish a barrier of protection to keep ants, and other crawling insects, from entering your home. Maggie’s Farm Yard Bug Spray is a hose-end spray that makes it easy to use about the outside of your house. Just reapply every 30 to 45 days to keep the barrier intact.
Maggie’s Farm Yard Bug Spray can be used around the perimeter of your house to create a repellent barrier of protection by preventing Argentine ants from getting inside. It will also kill them on contact. Plan to repeat spraying about every 45 – 60 days.
How do You Prevent Argentine Ants?
There are several methods to protect your home and property from Argentine ants. Like all ants (and bugs in general), they are attracted to sources of food and moisture, and often shelter.
Remember that Argentine ants are resilient, and their populations can bounce-back after being eliminated because they reproduce so readily.
To prevent Argentine ants:
Eliminate standing water around your home by emptying (or refilling with fresh water) birdbaths, flowerpots, kiddie pools, buckets, pet dishes, etc.
Clean up food and drink spills immediately, and keep food stored in tightly sealed containers. Keep trash in sealed containers and remove daily.
Trim tree branches and other shrubbery around your home so that it doesn't touch the side of the structure.
Seal cracks, crevices, holes, utility line entry holes around your home, too, to minimize their ways to get in.
Store firewood and building materials at least 20 feet away from the house and remove yard debris regularly, as these make for perfect Argentine ant nesting areas.
You May Need to Call a Professional
There's a lot you can do yourself to help manage Argentine ants you may find in your home or yard. If an ant invasion is more than you are able to handle, call a pest control professional.
Remember, a large and long lasting infestation can result in serious damage to your home!
For more general help with ants, read the following articles:
What are your Argentine ant control tips and tricks? We want to know! Leave us a comment below!
For scientifically-tested, effective ant control in your home, yard, and garden that is friendly to the environment, try Maggie’s Farm pest control products. Our promise is that our plant and mineral-based products are developed by scientists and seasoned pest control professionals to be the most effective.