Ants brochure coverIdentifying and Controlling Argentine and Darwin's Ants

This page provides tips on how to control Argentine and Darwin's ants - and provides information about the spread of this invasive pest.

These two species of ant have been included in the Regional Pest Management Strategy because of their potential impact. Occupiers of ant-infested properties are required to control them. There are a range of treatments available.

Identifying Argentine and Darwin's Ants

  • Argentine and Darwin’s ants are a honey brown colour when viewed in sunlight. Most of the more common house ants are black.
  • Argentine ants are slightly bigger (2.5 – 3mm) than Darwin’s (2.0mm). Darwin’s ants give off a strong odour when crushed.
  • Both species form multi-queen colonies and will become completely dominant within a couple of years of arrival in an area.
  • Both species build nests underground, usually within a few metres. Their nests will be distributed throughout a section with a preference for barked areas, shrubberies and compost heaps.
  • Both species react frantically when their nest is disturbed.
  • Both species will trail up shrubs and trees to “farm” (tend and protect) scale insects and aphids in return for honeydew.
  • They forage to seek food and their trails are generally located along edges e.g. curbing, retaining walls, pathways, drives, cracks, garden edging, up shrubs and trees and up your house’s outside foundations or wall to an entry point. They will travel indoors to seek food if outdoor supplies are limited.

Argentine and Darwin's Ant Distribution

Argentine and Darwin's ants have only become established within Tasman District within the last two decades but have spread rapidly through urban areas and are starting to spread onto rural land.

Despite an aggressive campaign to contain them within the urban areas, they have continued to spread, and the present tools are not providing effective control. There is concern about their impact on activities in homes and gardens, in resthomes and hospitals, and their potential effect on horticultural crops and on native fauna.


These maps provide an indication of the location of the major infestations of Argentine and Darwin’s ants within the areas administered by Tasman District Council and Nelson City Council as at April 2016.

Control Methods

Residents who want to treat their own properties can use a bait, a spray or a granular insecticide. Pest contractors who are approved handlers can use products with a residual effect. There is further information in the brochures listed below. More comprehensive information is also available on the website below.

Read about Biff Ant product and the certified applicators in the Nelson Tasman region.

Video Seminar


Further Information

The following are technical reports about Argentine and Darwin's Ants