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Argentine ant

Argentine ant

Updated 12 January 2018 3:28pm

Argentine ant
Linepithema humile
Photo: Jack Kelly Clark, University of California

Why are Argentine ants a problem?

Argentine ants pose both a biosecurity and human health risk to the Wellington region. They are extremely invasive, with a rapid rate of reproduction. Argentine ants are highly competitive for resources, eating nectar, other insects, seeds, carrion and honeydew from aphids. Argentine ants are aggressive towards native ant and invertebrate species and will dominate an area through population numbers. They have also been observed attacking nesting birds and their young.

Argentine ants will invade residential and commercial buildings, causing human nuisance. Argentine ants can bite, causing a reaction in some people.

Description and background

Argentine ants are a small honey brown ant, 2 to 3mm long. They form large nests which can expand to super colonies. Queen ants do not have wings, and there can be multiple queens in a nest. Argentine ants travel in large distinctive trails, often five or more ants across. If a column of Argentine ants is blocked with an object such as a pen, they will travel over rather than around it. Unlike the other common native and introduced ant species of the region, Argentine ants do not give off an odour when crushed.

What can I do?

Argentine ants can be difficult to identify, but if an ant colony matches the description above, please contact MAF BNZ or Greater Wellington. A number of the private professional pest control operators are knowledgeable in ant identification and are experienced in controlling ant infestations of all types. There are a range of commercial ant control products available on the public market, which can be purchased from hardware and garden stores.

Additional information can be found at –

Argentine ants in New Zealand

Landcare Research Argentine ant identification

Tasman District Council information on Argentine ants

DOC's Argentine ant information