4954 N. Shamrock Place, Tucson, AZ 85705

Argentine Ant

Linepithema humile

Argentine Ant

Physical Features

Argentine ants have three body parts, six legs, antennae, and coloring ranging from light to dark brown. Thorax is unevenly rounded and hairless. Compound eyes, but virtually blind. One bump (node) is between the thorax and abdomen. The size and identifying characteristics vary upon caste members: queens-1/6 to 1/4 inch, workers-half the size of queens, and males-wings.

Life Cycle

Complete metamorphosis
Development takes 33-141 days from egg, larva, pupa, to adult forms. Adult forms have a caste system with defined roles within the colony. Workers make up the largest population in the colony. They protect the colony, gather food, and construct the nest. Many queens exist in the colony. They produce eggs, care for developing forms and groom. Males reproduce then leave the nest. They are attracted to lights.


  • Diet: Not Selective, especially sweets
  • Activity: Day and night
  • Preferred Climate: Warmer climates. Travel deeper into soil or indoors in cold and wet seasons.
  • Defense: Highly aggressive against other ant species eliminating other ant species in territories they invade.
  • Cautions: Emit a greasy, musty odor when crushed, capable of biting when disturbed.
  • Home Invasion: Trails of ants will be seen traveling along baseboards, carpet edges, furniture lines, etc. These ants will be searching for any food.

Helpful Hints

Sanitation practices to eliminate food sources.

  • Keep well-maintained landscape.
  • Recommend regular pest control service plan.

Interesting Facts

The large population of invasive Argentine ants in California has been contributed to the sharp decline of the coastal horned lizard population. Studies have shown that these lizards cannot process adequate nutrients when digesting this species; therefore, they are unable to maintain their weight.


They may bite when provoked.

Nesting Sites

Nests are located in moist but not wet areas. Indoors they are located near water pipes, sinks and plotted plants. Outside they are generally located under stones and boards, beneath plants, in fallen and rotting tree limbs, in tree stumps and along sidewalks.