Argentine Ant (Linepithema humile) Identification Guide

Identification

Argentine ants are light to dark brown, measuring about 1/8 inch in length. They have a segmented body with six legs and a single-node petiole. Unlike other ants, they do not have a noticeable stinger. These ants produce a musty odor when crushed and form massive colonies with multiple queens.

Lifecycle & Reproduction

Argentine ants undergo complete metamorphosis: egg, larva, pupa, and adult. Queens lay eggs continuously, allowing colonies to grow rapidly. Workers emerge within 2 to 3 months and live for several weeks, while queens can survive for years. Colonies can merge to form supercolonies, enhancing their survival and spread.

Habits, Diet & Behavior

These ants are aggressive foragers, primarily consuming sugary substances like honeydew from aphids. They also feed on proteins and fats. Unlike many ant species, Argentine ants form cooperative mega-colonies, reducing competition and making them difficult to control.

Where You’ll Find Them / Typical Locations

Argentine ants nest in moist environments, typically found in:

  • Near sidewalks and building foundations
  • Under logs, mulch, and stones
  • Inside wall voids and electrical boxes
  • Kitchens and pantries searching for food
  • Potted plants and garden beds

Threats & Danger

Argentine ants are nuisance pests that invade homes in large numbers. They displace native ant species and farm plant-damaging aphids for honeydew. While they do not bite or sting, they contaminate food and surfaces, spreading bacteria.

Prevention

  • Seal cracks and gaps around doors, windows, and foundations
  • Eliminate food and water sources inside the home
  • Store food in airtight containers and clean up spills promptly
  • Trim vegetation away from structures to reduce nesting sites
  • Use ant baits to disrupt colony growth

Signs of Infestation

  • Large trails of ants moving in and out of structures
  • Presence of small, dark-colored ants in kitchens and pantries
  • Increased aphid activity on plants due to honeydew farming
  • Nesting under stones, logs, and in moist outdoor areas
  • A musty smell when ants are crushed

How to Get Rid of It

  • Use bait stations containing slow-acting insecticides to target the colony
  • Apply perimeter insecticide treatments to entry points
  • Remove nesting materials such as mulch and debris near the home
  • Reduce moisture sources, including leaky pipes and standing water
  • Consult professional pest control for extensive infestations