Biosecurity alert: Red Imported Fire Ant

Page last updated: Wednesday, 12 February 2020 - 4:27pm

Fremantle port workers, residents and businesses are asked to report sightings of unfamiliar ants, following detection of one of the world's worst invasive ant species in Fremantle.

Western Australia is currently free from RIFA. If it became established in WA, it could severely damage the local environment, Australia's outdoor lifestyle, and agricultural and tourism industries. RIFA inflict a painful, fiery sting, which in rare cases can cause an acute allergic reaction.

Treatment and surveillance activities are underway, and a quarantine area has been established. 

Report your observations using the MyPestGuide Reporter app or online at

Reporting options

Report any unfamiliar ants immediately – even if unsure. Do not touch ants or disturb the nest as they may aggressively defend it. Do not send in live samples. Take a photo if safe to do so.

Contact the department via:

Eradication activities

The Department Of Primary Industries and Regional Development detected red imported fire ant (Solenopsis invicta) at two adjoining businesses at Fremantle Ports in November 2019.

A small number of nest entry points (six) in close proximity were found as part of routine surveillance. Department officers have moved quickly to treat the infestation and destroy the ants.

The department is also undertaking surveillance of the port and surrounding areas to determine any spread of the pest. So far, no more nests have been found.

Quarantine area established

To support response efforts and prevent any potential spread of the pest, a Quarantine Area Notice (QAN) been put in place for parts of Fremantle.

map of quarantine area

Quarantine Area boundaries

The Quarantine Area extends from Port Beach, as far south as the South Fremantle dog beach and east to East Street. Streets included are listed below:

Coast line of Rous Head south from Port Beach, coast line of Rous Head with the Inner Harbour, Queen Victoria Street, coast line of Fremantle and South Fremantle until South Fremantle Dog Beach, west side Marine Terrace, north side of South Street, west side of South Terrace, north side of Douglas street, west side of Carnac Street, north side Wray Avenue, west side of Hampton Road, north side of Stevens Street, west side of Swanbourne Street (including Stevens Reserve), west side of East Street, north and south side of Beach Street (including North Worrall Park and East Street Jetty), west side Queen Victoria Street, south side of Tydeman Road, west side Port Beach Road and Port Beach.

The QAN introduces restrictions on moving the below risk material to areas outside of the quarantine area.

Quarantine Area risk material

  • Potted plants
  • Plant mulch, bark and wood chips
  • Hay and straw
  • Manure
  • Soil (including soil attached to non-potted plants, potting mix, and any form of manufactured potting media, pebbles and gravel)
  • Grass and turf (including grass sod with soil attached)
  • Soil, turf, grass or other organic matter that has or appears to have been part of a nest or mound built by RIFA
  • Any machinery or equipment used in digging, earthmoving or disturbing of soil
  • Shipping containers

Quarantine Area restrictions for residents

Restrictions DO NOT apply to risk material that have been in the quarantine area for less than five days.

The below restrictions apply only to items used for domestic purposes

  • Potted plants can be moved if re-potted with commercial soil from a sealed package, and moved within 2 days of re-potting.
  • Potted plants can be moved if chemically treated.
  • Turf can be moved if treated with cover spray.
  • Some other affected items can be moved if heat treated or fumigated.
  • Refer to the Quarantine Area Notice for chemical and heat treatment options, associated movement periods and safety advice. Chemicals should be used as per label instructions or APVMA permit.

Quarantine area restrictions for business

Restrictions DO NOT apply to items that have been in the quarantine area for less than five days.

The Department will assist businesses to ensure the below movement restrictions have minimal impact on business operations. The below apply only to items used for commercial purposes. 

  • Risk material and equipment/machinery may be moved if approved by DPIRD. Contact DPIRD’s Pest and Disease Information Service on 9368 3080 for movement authorisation.
  • Shipping containers may be moved if they are free from any RIFA host material or RIFA nest material. This will require businesses to undertake a visual check and if needed the same clean-down procedures used for all biosecurity risks (see below).

Clean-down procedures 

  • physically remove the material (e.g. scraping or blowing)
  • brush down
  • wash down or steam clean
  • air blast with an air compressor.

Components requiring inspection

  • Cargo container - interior, exterior, locking mechanisms
  • Bulldozer - rippers, blade, track frame, belly plate
  • Excavator - track frame, underside of slew ring, buckets
  • Drott - track frame, rippers, belly plate
  • Grader - rippers, mould board
  • Motor scraper - overflow area on rear of scraper
  • Tractor and slasher - top of slasher, skids
  • Backhoe - buckets and backhoe attachment
  • Bobcat - buckets, belly-plate/other attachments
  • Trucks - soil build-up in bins, chassis rails.

How to identify Red Imported Fire Ant


Many different sized ants can be found in one nest


Red imported fire ant (RIFA), Solenopsis invicta, is one of the most serious and invasive ant pests in the world, because of its harmful effects on people, agriculture, flora and fauna, infrastructure and recreational activities.

Below is information on what to look for. This identification video (courtesy of the National Red Imported Fire Ant Eradication Program) may be useful if you are looking for nests or observing ants.  Although please keep in mind any RIFA nests in WA will look different to nests in Queensland due to our sandy soils.

What to look for

  • Hard to distinguish from common native ants.
  • 2-8mm, reddish brown in colour with a darker abdomen.
  • Ants of varying sizes in one nest.
  • Nests that often have no visible entry holes like other ant nests.
  • Young nests can be indistinct or start out as small piles of excavated soil.
  • A fiery sting that can blister and form pustules at the sting site.

Where to look

RIFA nests may be found next to or under other objects on the ground, such as timber, logs, rocks, pavers or bricks. Look near pots or any areas of disturbed ground as well as:

  • pot plants on the ground
  • stores of topsoil, mulch and potting mixes
  • open areas like lawns, firebreaks or fence lines.
  • under landscape materials (e.g. logs, stones)
  • under timber or pallets on the ground
  • adjacent to buildings and other structures
  • 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.