Argentine Ant

Official Name

Linepithema Humile

Size

3 mm (worker ants); 10 to 12 mm (queen ants)

Color

Light to Dark Brown

Geographical Location

Southern U.S. and California

Common Household Location

Outside Landscaping, in Mulch or Under Slabs

Identifying Characteristics

  • These ants give off a musty odor when crushed
  • Uneven thorax when seen from the side

Official Name

Linepithema Humile

Size

3 mm (worker ants); 10 to 12 mm (queen ants)

Color

Light to Dark Brown

Geographical Location

Southern U.S. and California

Common Household Location

Outside Landscaping, in Mulch or Under Slabs

Identifying Characteristics

  • These ants give off a musty odor when crushed
  • Uneven thorax when seen from the side

Notes

The Argentine ant is one of the most invasive species in the U.S. They do not sting or bite humans but are extremely aggressive toward other ants. They will attack other species, overwhelming them with sheer numbers. Argentine ants have overcome fire ants and red harvester ants, defending and expanding their domain.

 

Argentine ants create massive and fast-growing nests, with as many as 300 queens for just 1,000 workers and millions of ants in each colony. They can quickly relocate their nesting area, making them difficult to displace. They regularly move eggs between nests and can even be spotted carrying the tiny white bundles from one location to the next.

 

These are trailing ants, so you’ll typically see them in long, neat lines. They can travel more than 200 feet for a food source and will send thousands out in a single party in search of food. Worker ants in these colonies are exclusively female and uniform in size. Queens are about twice as large as the workers, making them easily visible when they’re relocating from one nest to another.

 

You can find Argentine ants in any open cavity in trees, shrubs or branches, beneath mulch, and underneath wood. They build shallow nests, just an inch or two beneath the surface. Inside the house, Argentine ants can make a home in nearly any crevice. They may nest in beds, clothing, and appliances. They prefer damp environments and may also make a home near water pipes or in the bathroom.

 

Argentine ants have a varied diet and can feast on fresh fruit, budding plants, and both oily and sweet foods they find in the home. They will also feed on the honeydew produced by other insects. The ants tend these species, preferring scale bugs and aphids, protecting them from predators in exchange for the sustenance. For protein, they may eat small insects.

 

Infestations are typically large and difficult to control. The best approach to Argentine ants is prevention. You should eliminate any ground clutter around your home, including decaying plant material or wood piles. Do not overwater flowerbeds, as this is a prime draw for these ants. Keep the kitchen meticulously free from crumbs and spills and seal all food containers. If you have an active infestation, contact an experienced exterminator to help you come up with a plan for baiting and eradication.