Fire ants

Red imported fire ant (Solenopsis invicta) is one species of fire ant. Another species, tropical fire ant (Solenopsis geminata), has been found in the Northern Territory. For easier reading, the term 'fire ant' in this context refers to red imported fire ant.

Close-up of red imported fire antFire ants pose a serious threat to our environment and have had significant environmental, health and economic impacts in other countries. The red imported fire ant has been found in Queensland, which has put Victoria on alert.

Red imported fire ants are native to South American countries including Brazil, Paraguay, Uruguay and Argentina. They entered the southern United States in the 1930s (probably in soil used as ship ballast) and have continued to spread, infesting most of 11 southern states and even California. Red imported fire ants were unknowingly imported into Brisbane over 20 years ago.

The impact of fire ants

Fire ants will affect everyone. They have the potential to:

  • limit Australia's outdoor lifestyle
  • devastate our environment
  • reduce production of some agricultural industries

Fire ants will also negatively impact land and business values and threaten our orchards, crops and pastures. They may potentially jeopardise our 'naturally', clean and green export image.

If fire ants sting children and pets they cause serious distress.

Bare arm showing fire ant bites

Fire ants can:

  • inflict a painful, burning sting
  • damage equipment and infrastructure
  • reduce property values
  • invade backyards, parks and recreational areas
  • impact native flora and fauna
  • injure animals and damage crops.

The potential economic burden is also a major concern. The Australian Bureau of Agricultural and Resource Economics has predicted a cost to Australia of $8.9 billion over 30 years, if the ant is not controlled.

Surveillance and prevention in Victoria

Victoria has a low risk of infestation of fire ants. Fire ants are currently not known to occur here, however there were 2 detections in Victoria during 2001. One was in the Dandenong area amongst pot plants shipped from Brisbane, the other was in soil in a shipping container from the USA. Both infestations have been eradicated.

Swarm of fire ants crawling over a dollar coin

Fire ants are a declared exotic pest in Victoria and a comprehensive set of regulations are in place to control the movement of high-risk materials from Queensland, including:

  • nursery plants
  • potting mixtures
  • mulches
  • soil
  • equipment

If discovered, a well planned eradication and containment program will immediately be put in place. Victoria is also contributing to the national eradication program being conducted in Queensland, where fire ants are established around Brisbane.

Identifying fire ants

The red imported fire ant is very similar to several local ant species.

They are:

  • small, 2 to 6mm long
  • reddish-brown with a dark brown abdomen at the rear
  • very aggressive
  • agitated when disturbed
  • inflict a fiery sting causing blistering and sometimes an allergic reaction
  • nest in soil.

Common ants in Victoria are not so aggressive and will usually run away from any disturbances.

2 images of mounds on grounds that are fire ant nests

Red imported fire ant nests vary in shapes and sizes depending on age and soil type.

They are:

  • usually closed (no central opening)
  • a dome shaped mound
  • up to 45cm high
  • commonly in open areas with full sunlight.

Native ants build smaller nests that have an obvious opening. If you find any nest, do not touch it — contact the Customer Service Centre on 136 186.

High risk materials

Fire ants are spread most commonly through transportation of :

  • pot plants
  • soil
  • mulch
  • potting mix
  • baled hay or straw
  • landscaping and construction materials
  • machinery and equipment
  • aquaculture containers
  • timber or pallets.

These must be checked carefully and appropriate inquiries made when transporting the above products from infested areas.

Do not transport any materials that have come in contact with fire ant-infested ground.

What to do if you suspect you may have fire ants on your property

If you think that you have found fire ants, contact the Customer Service Centre on 136 186.

Do not disturb fire ant nests. Any disturbance may encourage the colony to move somewhere else and this can make eradication more difficult.

If you are sure that you have fire ant feeding sites and nests, you have the option of taking immediate action. You can employ a professional pest controller, or you can use ant bait which can be taken by ants into the nest. However, it is vital that you report any suspect ant colonies to us.

Ensure that fire ant colonies are not spread from your property.

Make sure that materials infested with live fire ants are not placed in your wheelie bin.

Reporting an unusual pest or disease of plants or honey bees

Report any unusual plant pest or disease immediately using our online reporting system. Early reporting increases the chance of effective control and eradication. Please take good quality photos of the pests or damage to include in your report where possible.

Alternatively, you can call the Exotic plant pest hotline on 1800 084 881.

Report online

Page last updated: 25 Jan 2023