How To Identify and Inspect Argentine  Ants

The picture above is an Argentine worker ant. The Argentine worker ants are the ones most commonly spotted. They are light to dark brown and are about 1/12–1/8-inch long. They have a uniform dull brown color. Their antennae are strongly elbowed (12 segments), and there is a single node in front of the abdomen (the waist). The Argentine ants are one-node ants. The Petiole (the node that separates the thorax from the abdomen) has one erect node. The thorax (middle part supporting the legs) on the Argentine ant has an uneven shape when viewed from the side.

• Workers: About 1/8inch in length
• Queens range from 1/6 to1/4 inches in length.
• Legs are in proportion to the body
• Their antennae are divided into 12 segments
• Their eyes are set below the widest point of the head
• Emits a musty smell when crushed
• A single node separates thorax and abdomen
• They move in large ant trails

Photo and ID text courtesy of UC IPM Online

Get Rid Of Argentine Ants

Get rid of Argentine ants with the Mega-Colony Ant Kit.

Argentine ants are megacolony ants with an enormous capacity for growth and expansion due to their many queens and splintering off to new colonies. These ants can have many nests with hundreds of queens and thousands of workers. Their usual habitation is outside, but these ants can present a problem when they come inside foraging for food. They rarely nest in walls of buildings, as some other ants commonly do. They enter to hunt and then exit, returning to the nest. Since Argentine ants are so invasive, it may be difficult to control with one single product. This kit combines recommended ant baits and a non-repellent insecticide.

Inspect For Ant Nests

These ants like to nest in moist soil next to buildings or under them, particularly near plants and sidewalks. These nest maybe only 1-2 inches beneath the surface. Look for these nests under rocks, beneath boards and plants, beneath lumber, and debris.

They nest near water and food sources. They often seek shelter inside, when conditions outside are either too dry or wet.

Argentine ants will nest inside in areas that are not soil related. They may nest inside a structure, such as a bathtub set above a slab foundation, under expansion joints on slabs, under insulation in an exterior wall void, and in interior potted plants. Inside, Argentine ants may nest in wall voids, around drains and pipes, and in insulation

Foraging ants will enter the house when outside conditions are extremely dry or wet. The foraging worker ants will travel along regular paths from the nest and branch out to explore an area. Their foraging patterns may be so extensive as to incorporate a next-door neighbor's yard. Baiting would be the best solution in these cases.

Most Argentine ants establish new nests by swarming to mate. These ants mate inside the nest from reproductives produced inside the nest.

Argentine ants are incredibly mobile and will relocate colonies frequently. They will establish new colonies many times because of many external factors such as food sources, changing temperature, and proximity to woody plants.

Tracking Argentine ants can be easy because they generate active pheromone trails when foraging. In many areas, you will see pheromone trail super-highways three and four lanes wide.

Musty Smell

A musty odor is emitted when the Argentine ant is crushed. The Odorous ant also has a musty smell when crushed and is a one-node ant, but the node shapes are different. The Argentine ant node is pointed, and the abdomen hides the Odorous ant's node. Argentine ants may be confused with the Crazy ants and Small (False) Honey ants, but the Crazy ants and Small (False) Honey ants have a circle of hairs at the tip of the abdomen, while the Argentine ant does not have hair on the tip of its abdomen.