The Argentine ant grows to about 1/8 inch long and all workers are the same size.
They are shiny and range in color from dull gray-black to gray-brown.
Argentine ants build shallow nests in the soil beneath stones, concrete slabs or other debris. They may also be found in piles of lumber, bricks, landscape mulch, insulation, walls and trees. Argentine ant colonies can grow very large with tens of thousands of workers and multiple queens. Colonies often combine becoming one huge super-colony extending over several residential properties. Argentine ants are very aggressive and will drive out other ant species.
Their primary food source is the sweet honeydew produced by aphids and mealy bugs. Protein foods may be part of their diet, but Argentine ants prefer sugar and will also dine on household food products and garden fruits. They enter houses in search of food and water. Argentine ants are fond of sweets, tuna, syrups, juices, eggs, dead spiders and rodents, vomit, feces and just about any other organic matter they can find.
Colonies contain thousands of workers and many queens, and mating takes place within the confines of the colony. Queens are the only ones that lay eggs. Since Argentine ants have as many as eight queens for every 1,000 workers, they raise more babies, making it very difficult to kill a colony.
Though the Argentine Ant is a small, non-stinging ant, it is very territorial and aggressive and will drive away or kill competing ant species. They make a chemical called iridomyr-mecin which they smear on their enemies to kill them or make them run away. Neighboring colonies of Argentine ants appear not to be aggressive toward each other, allowing for the rapid spread and domination of this species.
The most important step when dealing with any ant infestation is to find the source.