Fire ants

Fire ant treatment frequently asked questions

As part of the National Red Imported Fire Ant Eradication Program (the program), Biosecurity Queensland undertakes a baiting program for fire ants on targeted properties. This webpage answers the most common questions about fire ant bait treatment, and some information about the alternative method of treatment: direct nest injection.

What chemicals are used in the fire ant baits?

Fire ant bait is made up of corn grit soaked in a mixture of soybean oil and an insect growth regulator (IGR) – either S-methoprene or pyriproxyfen. S-methoprene is widely used in mosquito control programs, and pyriproxyfen is commonly used in dog and cat flea collars.

How does the bait treatment work?

The bait is thinly distributed across backyards and garden areas as well as parklands and paddocks. Any foraging fire ants in the vicinity will collect the bait and take it back to the nest.

The IGR within the bait leads to the sterilisation of the queen ant, preventing her from producing any more worker ants. After the last adult workers have died of old age (approximately 3-4 months) the queen is effectively starved, and the nest will naturally die out.

The IGR also affects the reproductive ants by causing them to drop their wings and prevent them from being able to spread naturally through flight.

How much of each chemical is used?

On an average suburban residential block (approximately 500 m2) about 100 grams of bait will be used, which is around a half a teaspoon per metre2. As the corn grits consist of 0.5% insecticide, very little active ingredient is distributed.

How safe are these chemicals?

The bait treatment is not harmful to humans or animals, as it is specifically targeted at fire ants. After the baits are distributed, they rapidly break down in direct sunlight.

The baits are used according to the conditions prescribed on the relevant product labels and permits from the Australian Pesticides and Veterinary Medicines Authority APVMA; an Australian Government regulatory body) to ensure safety to humans, animals and the environment.

Are these chemicals safe during pregnancy?

Scientific testing does not indicate that these insecticides can cause birth defects. The way these baits are used pose no risk to pregnant women or their unborn babies. However, it is always important to minimise exposure to all chemicals during pregnancy.

What precautions do I need to take?

The fire ant bait treatments pose no risk to public health or the health of pets. No specific health precautions by householders are considered necessary. It is quite safe to walk on ground that has been treated with bait.

What should I do if my child swallows some bait?

Exposure to active chemical is likely to be very low, particularly after a day or more has passed since the bait was applied. As these chemicals are of very low toxicity, no adverse effects would be expected if any bait were to be swallowed. However, if you have any concerns, seek medical advice from your family doctor.

What should be done if I think someone has become sick from the baits?

Given the low toxicity of the baits, no adverse health effects would be expected from the bait. However, if you do think someone has become sick as a direct result of fire ant baits, first, ensure that medical advice and attention is sought from your family doctor. Please notify Biosecurity Queensland by calling 13 25 23, following consultation with your doctor.

How is the bait distributed?

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

  • foot - with a hand held spreader
  • all-terrain vehicle (ATV) or quad bike
  • 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 larger properties. Large acreage properties are planned for aerial treatment as it can deliver broad scale treatment over large areas in an accurate, timely and cost efficient manner.

Do I need to take any precautions after my property has been treated?

For treatment to have the best chance of success, you must not water, mow or disturb your lawn, gardens or paddocks for 24 to 48 hours to allow for foraging fire ants to collect the bait. The active ingredient in the bait breaks down in a matter of days.

Also be aware that restrictions apply to the movement of materials that could carry fire ants such as soil, mulch, animal manures, baled hay or straw, potted plants and turf.

Before moving materials that could carry fire ants, please visit our fire ant movement controls page.

How regularly is this treatment required?

Properties within the designated treatment area are required to be treated two or three times between the months of September to May (weather permitting). Repeated rounds of bait treatment may be required over consecutive years, to eradicate fire ants from your area.

Bait treatment is only conducted during the warmer months when the ants are actively foraging for food.

How much does treatment cost?

There is no cost to you when your property is treated for fire ants.

Who will enter my property?

Only Biosecurity Queensland authorised officers will enter your property or site. Officers are easily identified by their uniform and identification badges. Program vehicles have signs identifying these as ‘Biosecurity Queensland’ and/or ‘Fire ant program’.

Can I refuse entry to my property for treatment?

Under the Biosecurity Act 2014, Biosecurity Queensland authorised officers can enter any property to conduct treatment and surveillance activities for fire ants. Entry to all properties for treatment and surveillance is essential in eradicating fire ants and a resident cannot refuse access. Under the Act a person must not obstruct an authorised officer in the exercise of an authorised person’s powers or penalties can apply.

Why does my property require treatment if I don't have fire ants?

The baiting program for fire ants operates on all properties in known fire ant areas or areas that may be at risk of becoming infested. Immature nests could be on your property and not visible until they mature.

Why are flags no longer used to mark the location of fire ant nests?

With the Ten Year Eradication Plan in progress, key program activities are continually being reviewed to ensure processes are effective, contribute to the broader program objectives and purpose, and are efficient and compliant with all appropriate protocols and procedures.

The program’s use of flag markers (flags) has previously been to assist as a visual aid for program treatment staff. However, the flags have been identified as potential hazards by becoming caught up in machinery causing expensive repairs, removed inadvertently through livestock movement, removed or shifted by members of the public, and used in hazardous situations (being thrown).

This has also impacted treatment efficiency.

Some members of the community and various industries have also falsely interpreted the presence of the previously used pot markers or flags as the identification of fire ant nests.

As a result the program has reviewed and is generally phasing out its use of flags as a nest identifying mechanism and has moved to the use of spatial technology to locate reported nests. GPS coordinates are fixed and recorded at the point of sample collection. From a smart phone or tablet device, program officers are directed to the exact location of the specific nest to complete program activities including treatment. In some exceptional cases, such as large development sites, flags may still be used where there is a lot of activity with many workers moving on and offsite.

Fire ant bait or direct nest injection treatment – how is the type of treatment determined?

All fire ant infestation is assessed to determine the most appropriate response, which is either a containment or eradication treatment activity. Eradication treatment is the planned broad scale multiple applications of fire ant bait, and containment involves a direct nest injection (DNI) with insecticide.

Upon site inspections, further assessment of infestation density, nest contents and land use can result in a combination of treatment activity being scheduled to best respond to the particular site and infestation findings.

What is involved in direct nest injection treatment?

High risk infestation is generally treated by direct nest injection (DNI) with insecticide which is a method that kills the ants within three to five days.

High risk infestation is infestation which presents either a public safety risk such as on sporting fields and schools; or infestation which poses a spread risk such as infestation on areas around the program’s outer operational boundary or in land use associated with product movement.

Lower risk infestation is also treated by direct nest injection, and can take up to 8 to 12 weeks for properties to receive this aggressive treatment. Direct nest injection work is scheduled according to the prioritisation of the risk. To ensure the program is efficient, consideration for the work schedule is also by geographic area.

If circumstance or the extent of risk changes, residents are encouraged to re-contact the Program by calling 13 25 23.

Where infestation exists within the planned eradication treatment area (currently in the west, around Lockyer Valley, Scenic Rim, Somerset and Ipswich local government areas), and does not pose a risk to public safety or spread of fire ants, infestation may be more effectively treated with the multiple bait applications that occur during the warmer summer months (usually September to May).

Report fire ants

If you see any ants or mounds that you think may be fire ants, use your mobile device to take a photo and report online or call 13 25 23.

In this guide:

  1. Top 5 places to check for fire ants
  2. Living in fire ant biosecurity zones
  3. Fire ant biosecurity zones suburbs list
  4. Fire ant eradication treatment
  5. Aerial fire ant treatment
  6. Treatment of fire ants by the program
  7. Treatment of fire ants at home
  8. Fire ant treatment frequently asked questions
  9. Training and education about fire ants
  10. Fire ant biology and ecology

Print entire guide