Argentine Ant

Argentine Ant: Facts, Identification & Control

Latin Name:Iridomyrmex humilis


From light to dark brown. About 1/10-inch long. Antenna has 12 segments.


Readily adaptable and can nest in a great variety of places. Colonies are massive and may contain hundreds of queens. Nests are usually located in moist soil, next to or under buildings, along sidewalks or beneath boards. These ants travel in trails, foraging day and night.


Omnivorous, they can eat almost anything but prefer sweet foods.


Eggs are white and laid in summer. Larvae emerge after about 28 days. Adult stage reached in about 74 days.

Argentine ants may live in soil, under wood, logs, debris or mulch. They may also nest in branches and cavities of shrubs and trees. Their nests are often shallow, measuring up to two-inches in depth in open habitats.

Argentine ants are brown in color, measuring about 1/16- inch in length. They have a single node in their midsection. The eggs of the Argentine ant are pearly white in color and take one week to a few months to hatch. Like other ant species, Argentine ants pass through the development process called complete metamorphosis. The larval stage may take up to two months to reach completion. From egg to adult, the life cycle of Argentine ants ranges from two to five months.

Unlike some other species, Argentine ants have no soldier caste. All Argentine ants are the same size. They travel with well-defined trails between their web of nests and their food sources. Argentine ants feed on fresh fruits, buds of plants, sweets, honeydew and oily household foods.

While other ant species have seasonal nuptial swarming flights, Argentine ants do not establish new nests through swarming. In summer and spring, a queen Argentine ant will leave her nest on foot to establish new colonies. New nests are constructed around the original, and remain connected to the queen's old colony, so workers are sometimes shared between colonies.

Argentine ants kill other insects and invade human dwellings. Over time, the network of interconnecting colonies could become an infestation. Each colony of Argentine ants can contain millions of insects and multiple queens. These colonies can populate entire city blocks, and researchers have estimated that Argentine ant infestations grow at a rate of more than 200 meters annually.