They are known as one of the worst invasive species of all time and Australia’s climate and lack of known predators have created the perfect conditions for them to thrive. We are talking about fire ants and what to do if you spot a nest.

This ant is on fire!

They attack animals, have environmental impacts, cause health impacts in humans, and can affect the way we recreate.

Not being from Australia, they have no natural predators and are spreading fast.

This little ant is originally from South America (Brazil, Paraguay, Uruguay, and Argentina). They are extremely resilient and one of the few insects that can survive in most locations around the world.

While we are not certain of their precise arrival in Australia, they were detected in Brisbane for the first time in February 2001. We are not alone. Over time, many countries have become infested with fire ants including America, Japan, and others.

Some useful links

If you happen to find a nest in your yard:

• Report it via this link or call 13 25 23.
• The National Fire Ant Eradication Program has great resources for you.

You can check the fire ants' biosecurity zones (they are in place to help prevent spreading through human-assisted movement).

How do we recognise them?

Luckily, we can identify fire ants thanks to a few specific characteristics:

• They are copper brown with a darker abdomen.
• Their size is between 2 – 6 mm (within the nest you will see ants of different sizes).

Ouch! What to do in case of stings

Their sting is painful and if you are breathing normally, not showing any severe reaction symptoms, and don’t have a history of insect allergies, according to the National Fire Ant Eradication Program, you can:

• Apply a cold compress to relieve the swelling and pain.
• Gently wash the affected area with soap and water.
• Take an antihistamine to manage minor, localised reactions and itching.
• It is important to keep blisters intact.

If your pets get stung:

• Quickly move them away from the ants or the nest.
• Remove any fire ants from their skin or fur. You can brush them off while wearing a pair of gloves (by hand or with a brush or a comb). Don’t use a hose because it can trigger the ants to become more aggressive.
• You can give your pet a cool bath to provide some relief post-stinging.
• Call the veterinarian if the pet is in pain or showing signs of a potential allergic reaction.

Their homes

If you’ve found a nest but can’t see any ants, it’s still important to take care.

Even though fire ants are unable to regulate their body temperature, they can adjust their nests depending on the weather and surroundings to survive.

This means that:

• In warmer temperatures or periods of drought fire ant nests look like small patches of loose soil.
• In cooler temperatures or following rain, they are larger, more visible mounds.

Also of note:

• Nests have no entry or exit holes.
• The shape and size of the nest are never the same as it changes depending on how big the colony is and on the soil type.
• The ants never leave the nest via the surface but through underground tunnels. They only exit the nest via the surface when they need to defend it and attack. 
• Inside, the nest is made of galleries that look like honeycomb (but don’t try and look inside unless you want to get stung!).

Where can we find their nests?

Fire ants are establishing their homes all around! You can find their nests in residential, rural, and industrial properties.

• Residential: garden beds, utility pits, footpaths, lawns, gardens, taps.
• Rural: dams, fence lines, piles of organic matter, cultivated land, cropping land.
• Industrial: open spaces, machinery, storage sheds, organic waste materials, fence lines.

Why are fire ants a problem?

With no natural predators in Australia, fire ants are able to multiply unchecked and spread out of control. They are also extremely aggressive and will swarm to a perceived threat when provoked. Instead of attacking alone, fire ants usually attack in groups or colonies and release pheromones that signal other members to launch multiple attacks together, with no signs of stopping.

They can affect our health, the environment, and the economy and can even have a social impact.

• Human health – If you’ve ever been stung by one, you’d remember! Their sting is painful as they will sting several times until their venom sack is empty and their pincer will continue to bite until it’s removed from the insect. Their sting can sometimes cause severe allergic reactions.
• Economy – Fire ants can cost billions to a country’s economy. Fire ants increase costs to agricultural businesses (damaging crops, stinging livestock, and destroying equipment with their mounds) and can affect export arrangements to countries free of fire ants.
• Social – If fire ants infest our parks or sports fields, they could become unusable, with disastrous social and economic consequences.
• Environment – Fire ants can cause severe damage to the environment because of how easily they can spread (they can even raft to survive floods!). Some of the impacts (as reported by the National Fire Ant Eradication Program’s website) include:

          - Eating fauna that nests or feeds on the ground, including insects, spiders, lizards, frogs, birds, and mammals.
          - Displacing or eliminating native species.
          - Eating and damaging seeds, potentially causing major ecosystem changes over time.
          - Predating or disturbing insects and animals that pollinate native plants, which may also cause long-term changes to the vegetation of our bushland areas.
          - Attacking species that occupy areas within one metre above ground.

Sources: https://www.qld.gov.au/environment/plants-animals/animals/pests-diseases/fire-ants, https://www.fireants.org.au/.