Argentine Ants

Learn Why They Are in Your Home


In This Article:


Though the insect lacks a stinger, Argentine ants stand capable of driving away other invasive ant species such as imported fire ants. Overall, the species proves highly capable of adaptation due to their ability to survive off diverse food sources, produce impressive numbers of offspring with multiple queens, create satellite colonies and resist fighting with other Argentine ants.

Appearance / Identification

What Do They Look Like?

argentine ant
argentine ant


How Big Are They?
Unlike some ant species, worker Argentine ants are all similar in size and do not usually exceed 1/10 of an inch in length. Queens may grow as large as 1/4 of an inch, while winged males grow slightly larger than workers.


Workers range in color from light to dark brown, while queens are uniformly brown and winged males tend to remain dark brown in color.


The segmented body of the Argentine ant features sections for the head, thorax, and abdomen. Additionally, the insect possesses a segment between the thorax and abdomen called a petiole.

The species also has a pair of segmented antennae.

argentine ant identification

Scientific Classification: Linepithema humile

Geographic Range

Argentine ants originate in warm, humid environments and prefer a Mediterranean climate. However, the pests have been introduced in various parts of the world as an invasive species. Argentine ants populate areas of South America, southern Australia, northern New Zealand, the UK, Spain, Portugal, Italy, Greece, South Africa, the southern United States and California, and islands in the Atlantic Ocean. In the east, the insects are dispersed infrequently from New Hampshire to North Carolina.

Why Are They Here?
Argentine ants are considered an invasive species in the United States. During the late 1800s, the species was introduced to North America in New Orleans, most likely through coffee ships from Brazil and Argentina.


What Do They Eat?

Argentine ants maintain an omnivorous diet. The pests will feed on:

  • live or dead insects
  • honeydew produced by insects
  • various meats
  • pet foods
  • sugar
  • syrup
  • ripening fruit
  • dairy products
  • eggs
  • animal fats and waste
  • vegetable oil
  • garbage
  • sewage
  • dead animals
  • Liquids make up a considerable portion of the Argentine ant diet.

Life Cycle

How Large Are the Colonies?
Colonies formed by Argentine ants often grow quite large. The largest reported colony fluctuated between 50,000 and 600,000 ants.

Queens make up 10 percent of the colony population, while workers comprise the other 90 percent. Unlike most ant species, Argentine ant queens forage for food and groom the offspring.

Eggs are typically produced in spring and summer and queens prove capable of laying thousands in one season.

Argentine ants go through a complete metamorphosis wherein eggs develop into larvae, pupae and then adults.

How Long Do They Live?
The complete Argentine ant lifecycle lasts an average of two and a half months but can range from 33 to 141 days.


How Do You Find Them?

  • Look for adult ants especially in moist areas.
  • May notice the presence of a stale, musty odor in infested locations.
  • Look for evidence of outdoor nest sites under logs, concrete slabs, trash and organic mulch, as well as in rotten wood, bird nests, bee hives, and similar places.


As an invasive species with aggressive tendencies, Argentine ants can negatively impact local biodiversity.

Can Spread Diseases
The pests also contaminate food supplies and spread disease. Though adult Argentine ants do not need much food to survive, their frequent feeding on garbage, sewage and dead animals ensures they carry many diseases that humans can contract. When disease-carrying adults then feed on stored food in homes, the entire supply is spoiled.

The insects are also considered a nuisance since they infest in such large numbers.

Signs of Infestation

Because Argentine ants invade homes in large numbers, spotting adults usually means an infestation is present.

Where Do You Find Them in the Home?
The insects may be spotted on or in stoves, refrigerators, shelves, beds, wall voids, insulation and clothing, but they prefer moister areas around water pipes, dishwashers or bathtubs.

Furthermore, when a worker ant is crushed, it releases a musty odor. The frequent or prolonged presence of the scent serves as another sign of an Argentine ant infestation.


Do not overwater outdoor plants or water them too frequently, and keep vegetation around the house to a minimum yet well-maintained.

Repair leaks promptly to prevent the insects from accessing food and water sources.

Food Storage
Finally, store foods in ant-safe containers, do not leave pet food out and

How to Get Rid of Them

Due to the large numbers in which they typically infest households, Argentine ants usually require the attention of a pest control professional. While the use of baits may produce sufficient results, pest control professionals possess the necessary licenses and certifications to use insecticides which prove essential to the effective removal of Argentine ants from homes.