Fire ants are from South America and are native to the floodplains of the Paraguay River in Brazil, Paraguay and Northern Argentina. They entered the southern United States in the 1930s, probably in soil used as ship ballast, and have been spreading across the US ever since.

Fire ants would have been unknowingly imported into Brisbane, possibly up 20 years ago. The pathway of entry into Brisbane is unknown, but was possibly in a shipping container from the US or South America. There have evidently been three different incursions of fire ants into Australia: two into Brisbane and one to central Queensland, near Gladstone.

Three main infestations of fire ant nests have been found:

• one in the south western suburbs of Brisbane/eastern suburbs of Ipswich
• one in an area around the mouth of the Brisbane River
• one in Yarwun, central Queensland, which has been successfully eradicated.

Spread from the initial Brisbane infestations, before they were identified, lead to a number of small outlying infestations around the greater Brisbane area including Logan and Redlands. View a map of the fire ant restricted area.

Fire ants spread naturally through mating flights and budding and may also be spread by flooding:

• a mated female (queen) can fly up to 2 km
• a newly mated queen finds a suitable nesting site, sheds her wings and starts a new colony.

Human-assisted spread:

• via shipments of infested nursery stock, soil, or other high-risk materials
• potentially many other materials and containers stored in a fire ant infested area.

Fire ant nests can have a single queen or multiple queens. A new queen will lay up to 20 eggs initially. Eggs hatch in 7-10 days and become adults after 9-15 days. A queen can increase egg laying up to 800 eggs per day after initial hatching.

Key characteristics:

• Fire ant workers come in an unusual variety of sizes within one nest.
• Fire ant workers are small (ranging from 2 - 6 mm). 
• Fire ants are copper-brown in colour, usually with a darker abdomen.
• Fire ants inflict a fiery sting and are usually aggressive.
• Fire ant nests usually have no obvious entry hole.
• The inside of a fire ant nest has a honeycomb structure.
• A mature nest is often dome-shaped, if found in a paddock or in bushland, but can also be found under debris or other objects.

Look near pots or any areas of disturbed ground as well as:

• in pot plants on the ground
• in stores of topsoil, mulch and potting mixes
• under landscape materials (e.g. logs, stones)
• under timber or pallets on the ground
• adjacent to buildings and other structures
• in untidy or overgrown areas
• near areas of permanent water (e.g. the banks of dams, rivers, ponds, aquaculture containers)
• tufts of grass in open areas, where the soil is built up around the tufts.

Stings from fire ants cause a painful, burning and itching sensation that can last for up to one hour. Apply a cold compress (or ice) as soon as possible to the affected areas to reduce swelling and relieve pain. After a few hours (or even a day or two), a small blister can form at the site of each sting. To prevent secondary infection, wash the blisters gently with soap and water and be careful not to break the blisters.

In rare cases, fire ant stings can be lethal to people. If a severe allergic reaction occurs, please seek immediate medical attention.

See Fire ant impacts.

Biosecurity Queensland is using a low-toxic bait treatment, which consists of coarsely-ground corn soaked in soybean oil and an insect growth regulator (IGR), either S-methoprene or pyriproxyfen. S-methoprene is widely used in mosquito control programs in the Brisbane region. Pyriproxyfen is commonly used as an IGR in dog/cat flea collars.

The bait is applied by broadcasting it over an area using about a teaspoon per square metre. Worker ants take bait granules back to the nest, where they are passed among other ants and fed to the queen. These baits do not kill the ants but sterilise the queen and stop the larvae from developing. The worker ants are not replaced and the colony dies out.

There are three main methods of distributing the bait, including:

• by foot, with a hand held spreader
• by all terrain vehicle (ATV) or quad bike
• by air, using a helicopter.

The method of bait distribution varies depending on the size of each property and accessibility. Officers use hand-held spreaders on residential blocks and ATVs are used on properties larger than 5000 m². Properties larger than 5 ha are targeted for aerial treatment.

The bait treatment has very low toxicity to humans and animals. The bait is scattered thinly and any not taken to the nest following treatment will quickly break down by the next day.

The aim of the current program is eradication. Biological control of any pest will only decrease its numbers, and is therefore not part of an eradication program.

The US is using biological control agents from the fire ant's native habitats. One of these is the parasitic phorid fly. Although this fly controls only about 3% of the fire ant populations in South America, its presence frightens foraging ants and interferes with their ability to gather food. Phorid flies could be a useful addition to chemical control in heavily infested parts of the US, where even small differences are worthwhile.

Fire ant nests in Australia are destroyed when found, so phorid flies could not survive here.

Don't do it! 

Boiling water will kill some ants but rarely the whole nest. Remaining ants will just move to a new location. The risk of scalds or burns to people makes attempting this method of control dangerous.

Petrochemicals like petrol, diesel or kerosene are dangerous to handle and will kill any plant material they touch. Some of the residue remains in the soil and may leach or run off into ground and/or surface water to pollute the environment. The risk of injuries from fire and explosions makes attempting this method of control dangerous.

Yes. Monitoring of fire ant-infested areas has shown that 99% of known fire ant-infested properties are now fire ant-free. However, it's essential to find any unknown infested areas and treat them to ensure fire ants are eradicated.

A fire ant restricted area is any past or current treatment area. When a nest is found a buffer area is established around it for treatment. The treatment area then becomes a restricted area for the movements of high-risk materials for both within and to outside any restricted area. You can view maps of restricted areas or check if a property falls within a restricted area by entering the address into RASE (Restricted Area Search Engine)

Eradication over large areas, such as the infested parts of the southern US, would not be achievable. However, some newly infested US states such as California have been successful in ridding smaller areas of the pest using modern control measures. Biosecurity Queensland is encouraged by the Californian experience and is optimistic that the outbreak in Queensland is small enough for eradication to be an aim.

A site inspection must be undertaken on properties within the fire ant restricted area prior to any disturbance of more than 1 m³ of soil, regardless of the soil being taken off site or not. If the disturbance is less than 1 m³ an inspection is not required. Once inspection is completed and no suspect ant samples are taken, a Fire Ant Inspection Report certificate will be completed and distributed. These certificates are current for 28 days.

To request an inspection, contact Biosecurity Queensland 13 25 23 five working days prior to the work start date or complete a Site Inspection Request form online.

Fire ants can remain hidden in potting mixes, potted plants, mulches, soil, timber used in landscaping, and other nursery and landscaping supplies. If transported to other areas, these items can carry the pest. Biosecurity Queensland is working with businesses to ensure the risk of spread is minimised. Businesses who deal with high-risk materials within the fire ant restricted area should be on an Approved Risk Management Plan (ARMP). Businesses operating under an ARMP will have a Biosecurity Queensland Fire Ant Approved Business poster on display.

Yes! They could spread to your area. Biosecurity Queensland is implementing a comprehensive fire ant action plan. This involves a range of measures including surveillance to find them, controls on the movement of high-risk materials to prevent the ants from spreading, and controls to lessen their impact.

There are many ways in which we can all help prevent the further spread of fire ants and achieve eradication.

• Check your yard and local areas such as footpaths, parks and sporting fields and report any suspicious ants or nests.
• Obey movement controls when disturbing or moving high risk materials on your property if you live in the restricted area.
• Allow access to your property for Biosecurity Queensland officers to undertake surveillance or treatment.
• Purchase materials from a Fire Ant Approved business.
• Become a volunteer and participate in surveillance activities or community events to help spread the message.

Register your interest to become a fire ant volunteer ranger.