Fire Ants Detected in Sydney: What Inner West Residents Should Know

A red imported fire ant nest has been found at a freight and logistics site in Sydney's inner west, and authorities are now checking homes and businesses across a string of nearby suburbs. It's the first fire ant detection in the Sydney basin since a Port Botany incursion in 2014, and the reason fire ants have been in the news this week.

The short version: if you think you've found fire ants, don't touch or treat the nest. Take a clear photo from a safe distance and report it to the NSW Biosecurity Helpline on 1800 680 244. The full picture is below.

What was found, and where

Commonwealth officers found ant specimens in a surveillance trap at the Enfield Intermodal Logistics Centre, a freight and warehousing site in the Strathfield South and Enfield area, on 23 September. Testing confirmed them as red imported fire ants (Solenopsis invicta) on 25 September, and authorities located and treated a single nest: two mounds, built within concreted areas. The detection was made public on 13 October.

Detection dog teams have since swept the site and found no other nests there, but NSW authorities say there's some risk the ants had already spread beyond it. The response now focuses on inspecting and treating potential locations within 500 metres of the site, then surveillance out to 2 kilometres. Modelling by the state's Chief Invasive Species Officer, Scott Charlton, puts a 93 per cent chance on the ants having reached within 500 metres of the site, and a 23 per cent chance they got as far as 2 kilometres.

Genetic analysis shows the ants most likely arrived from overseas in a shipping container, and are not from Australia's main infestation in south-east Queensland. A Biosecurity Control Order covering the movement of high-risk materials such as soil, mulch, turf and plants is expected by the end of October, and a community information centre has been set up at Chullora Marketplace, 357 Waterloo Road, Greenacre.

Why fire ants get this much attention

Fire ants are one of the world's worst invasive species, and the concern goes beyond the sting. They prey on native wildlife, damage equipment like meter boxes and air conditioners by chewing through insulation, and can make parks and backyards hard to use once they take hold. Severe allergic reactions are rare but real: around 0.5 to 2 per cent of stings cause a systemic reaction, and up to 7.5 per cent of people stung seek medical help.

The encouraging part is that fire ants can be eradicated, and NSW has done it before, including right here in Sydney. Incursions in the Northern Rivers between 2023 and 2025 and a Port Botany incursion in 2014 were all destroyed. As Agriculture Minister Tara Moriarty said, while fire ants are one of the world's most invasive species, "they can and have been successfully eradicated in New South Wales."

How to spot fire ants

Fire ants are small, and their nests can be easy to miss. If you're checking your yard, here's what to look for:

• Size. Workers run 2 to 6 millimetres long, and unusually for ants, a single nest contains a mix of sizes.
• Colour. Dark reddish-brown, with a darker brown-black abdomen.
• Temper. Disturb a nest and hundreds of ants pour out at once, stinging repeatedly.

Nests look like mounds or flattish patches of crumbly soil, up to 40 centimetres high, with no obvious entrance hole. They turn up most in open, sunny ground: lawns, garden edges, near water sources and utility pits, and in exposed soil. They're rare in shaded bushland and inside homes. Several harmless ants look similar, and the National Fire Ant Eradication Program has side-by-side photos. If you're not sure, that's exactly what reporting is for.

What to do if you see them

The official campaign is three steps, and none of them involve touching the nest:

• Leave it. Don't destroy or treat the nest, and don't try to capture the ants. Fire ants are prohibited matter in NSW, and it's an offence to treat, move or possess them.
• Snap it. From a safe distance, take a clear photo or video of the ants or the mound.
• Call it. Report it on the NSW Biosecurity Helpline, 1800 680 244, or through the online form. If you're not sure, report it anyway.

And one thing not to do: don't treat it yourself. "Don't try to control or treat suspected fire ants yourself," the NSW Department of Primary Industries and Regional Development says. "Treating them yourself or calling a pest controller could cause them to spread." Over-the-counter products don't kill the colony, and disturbing it can scatter the ants into new nests. If fire ants are confirmed on your property, the government program treats the site at no cost to you.

If someone gets stung

Fire ants swarm when disturbed, and each ant can sting multiple times. The sting burns hard, often for up to an hour, and small pustules usually form within a couple of hours to two days. They can take up to 10 days to heal.

First aid, per the National Fire Ant Eradication Program: move away from the nest, wash the area with soap and water, apply an ice pack for pain and swelling, and use an antihistamine for itch. Don't break any blisters. Call 000 straight away for signs of a severe reaction: flushing, widespread hives, swelling of the face, eyes or throat, chest pain, rapid pulse, nausea, heavy sweating, breathing difficulty or faintness.

Pets are at risk too, especially animals that dig, because fire ants swarm around the nose, mouth and ears. Move your pet away from the nest, remove any ants with gloves or a brush rather than a hose, and call a vet urgently if there's facial swelling or trouble breathing.

If you live in the inner west

The response is focused on properties within about 2 kilometres of the site. The suburbs in or bordering the survey area include Strathfield South, Strathfield, Enfield, Croydon Park, Belfield, Campsie, Belmore, Lakemba, Chullora and Lidcombe. Wherever you are in Sydney, the same advice applies: keep an eye out, and report anything that looks wrong.

A few practical things while the control order is being finalised:

• Check your pots and garden beds. The Agriculture Minister's advice: "have a look at your pot plants and just make sure that there are no ants in them."
• Don't move soil, mulch, turf or plants out of the area. The coming order will restrict these high-risk materials, which are how fire ants mostly travel long distances.
• Watch for updates. The control order is expected by the end of October; the latest advice lives at nsw.gov.au/fireants.
• Ask questions in person. The community information centre at Chullora Marketplace, 357 Waterloo Road, Greenacre, is open to residents and businesses.

Quick answers about fire ants

Have fire ants been found in Sydney before?

Yes. A Port Botany incursion in 2014 was successfully eradicated, and this is the first Sydney-basin detection since then. NSW has also destroyed incursions at South Murwillumbah in 2023, Wardell in 2024 and Tweed Heads in 2025, with surveillance ongoing.

What if I'm not sure it's a fire ant?

Report it anyway. Officials would rather check a false alarm than miss a nest. A photo from a safe distance is enough; don't try to catch live ants.

Can I just spray the nest?

No. Fire ants are prohibited matter in NSW, so treating or moving them is an offence, and DIY sprays don't kill the colony. The government program handles confirmed nests under supervision, at no cost to the property owner.

Do fire ants live inside houses?

Rarely. They prefer open, sunny ground such as lawns, garden edges and areas near water and utility pits. Inside homes is one of the places they're least likely to be found.

Where do I report a sighting?

The NSW Biosecurity Helpline on 1800 680 244, by email at invasive.species@dpird.nsw.gov.au, or through the online form at dpi.nsw.gov.au/fire-ants. Outside NSW, the national program is at fireants.org.au.