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PEST WATCH ALERT: Yellow Crazy Ant

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The yellow crazy ant (Anoplolepis gracilipes) is listed as one of the top 100 worst invasive species by the IUCN and the Global Invasive Species Database.

Native to Africa, the yellow crazy ant has a long body and very long legs and antennae. Its name comes from its erratic walking style and frantic movements, with frequent changes in direction, especially when disturbed. Yellow crazy ants can disrupt natural environments, affect the horticulture industry, and cause skin and eye irritations. They are found throughout the Pacific region and on Christmas Island and are most commonly transported inside sea cargo.

The yellow crazy ant – Photo courtesy of NSWDPI

Yellow crazy ants are regularly detected and eradicated by the Australian Government’s Department of Agriculture in port areas. They have spread extensively in Queensland since they were first discovered in Cairns in 2001. Despite Biosecurity Queensland’s ongoing treatment and surveillance, eradicating yellow crazy ants is no longer considered possible in Queensland. Infestations have been found at light industrial properties in Maryborough and industrial estates in Hervey Bay, so we all need to work together to make sure this pest doesn’t make its way to K’gari. 

Environmental impacts from this pest include the disruption of native species, including birds, animals and plants, and the fact they will protect sap-sucking insects such as scale and mealy bugs.

Yellow crazy ants typically colonise moist, shady, disturbed habitats such as rainforest margins/gaps and agricultural land, particularly agroforestry. 

  • Yellow to brownish ant with a body about 5mm long.
  • The abdomen is dark brown, sometimes striped.
  • Legs and antennae are very long.
  • The body is long and slender.
  • Walking style is erratic.
  • May spray formic acid when disturbed.

The yellow crazy ant is listed as one of the world’s 100 worst invasive alien species by the International Union for Conservation of Nature and is a restricted tramp ant under the Biosecurity Act 2014.

If you think you have a yellow crazy ant infestation, please contact Fraser Coast Regional Council on 1300 79 49 29.


  1. Archemede Mario Tito says:

    99% positive that yellow crazy ants are to be found in 661 boat harbor drive Urangan QLD picked up a pot plant it was riddle with them running on my hand and arms. much thinner from a regular ant

    • finiaadmin says:

      Thank you so much for your report which I have forwarded to the Council’s Biosecurity Officer for further feedback and response. Did you manage to get a photo or could you get one? If you find a plant or animal – including YCA – then Biosecurity Queensland asks that you take a photo and email it, along with the location and date to info@daf.qld.gov.au.

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