Types of Ants :: Argentine Ants :: Printer-Friendly Version
Ant Origin & Distribution
The argentine ant is native to Argentina and Brazil and is believed to have entered the United States in the late 1800s on ships transporting coffee from Brazil. Argentine ants are common throughout the southeastern United States, southern California and Hawaii. Infestations have also been reported in Arizona, Missouri, Illinois, Indiana, Maryland, Oregon and Washington.
Ant Identification
Argentine ants vary in color from light to dark brown. The worker ants are about 1/10" long and the queens, which are larger than the workers, range about 1/8" to 1/4" in length. Workers smell musty when crushed.
Ant Biology
Argentine ants form widespread sub-colonies, each with multiple queens comprising about 10 percent of the population. These sub-colonies interconnect forming super-colonies with millions of ants often overwhelming other ant species and becoming the dominant ant over large areas. New colonies are formed either by newly mated queens, which mate in the nest without swarming, or by "budding" where one or more reproductive queens and a group of workers move away from a parent nest to form a new one. The colony lifecycle is seasonal.
Ant Habits
Argentine ants establish strong, easily seen trails, sometimes hundreds of feet long, which may contain thousands of ants traveling to and from their nests. Trailing is heaviest in early morning or late afternoon. It declines when surface temperatures exceed 90°F, but may continue where shade or cover offer protection. Although trailing is most evident during the day, activity may continue into evening hours until temperatures drop below 60°F. Outdoors, trails are commonly seen along the edges of patios, driveways, sidewalks and structural edges formed by bricks, siding and soffits. Indoors they may be seen along baseboards, cracks in floor tiles, corners of counters and under carpet edges.
Argentine ants may invade buildings in large numbers when conditions outside are too wet or too dry, or when there is a decrease in their natural food source, honeydew. They will travel along tree and shrub branches, utility lines, cables, wires, and on the ground next to foundation walls to find any crack, crevice or hole which allows entry into structures. Once inside, they may move about the structure via utility wires and pipes in wall voids in search of food and nesting sites. Once foragers find food, trails are reinforced to recruit more ants to the food source.
Argentine ants tend to form shallow nests located in moist situations such as under stones, logs, debris, firewood, potted plants, landscape mulch, along sidewalks, beneath plants and in crawl spaces. Nests are often found at the base of plants and trees that support honeydew-producing insects such as scale and aphids. Inside, these ants usually nest near a moisture source such as in wall voids near water pipes, sinks, bathtubs or showers, or in potted plants.
While they prefer sweet foods like sugar, syrup, fruit juice, honeydew and plant secretions, argentine ants will feed on almost anything including meat, eggs, oil and fat. Hundreds of argentine ants can be quickly recruited to contaminate accessible food items indoors. Although argentine ants are a major nuisance pest, they cannot sting.
Ant Control
If you think you might have an argentine ant infestation in your home, it's imperative that you contact a certified and licensed pest control professional
to inspect the situation and confirm identification. Experts will advise against do-it-yourself options, as it is much more efficient and cost-effective to have a trained set of eyes identify the correct ant species and recommend effective treatment options specific to an individual infestation. Improper do-it-yourself options may result in killing a few ants, while the rest of the colony simply relocates to other areas around and inside the structure.