Argentine Ants in New Zealand: How to Beat the Supercolony

What makes the Argentine ant so successful

The Argentine ant (Linepithema humile) is one of the world's worst invasive species, and it's well established in parts of New Zealand — particularly Auckland, Tauranga, Wellington and parts of the South Island. Individually small and inoffensive, it wins by sheer numbers and organisation.

The secret is the "supercolony". Most ant colonies fight any ant from another nest. Argentine ants don't — nests in the same supercolony are all friendly, sharing queens and workers across huge areas. A supercolony can stretch across whole suburbs, which is why killing one nest does nothing to dent the population.

How to identify an Argentine ant

• Workers 2–3 mm, light brown, all similar size.
• Trails are thick, fast and multi-laned, running along edges into homes.
• No strong smell when squashed (unlike Darwin's ant's coconut whiff).
• Multiple queens per nest — colonies spread by "budding" rather than flying.

Why spraying makes it worse

Because each colony has many queens and spreads by budding, killing the ants you see does nothing — the colony just grows back from the queens you never reached. A repellent spray can even trigger "panic budding", where the colony splits and spreads to new nesting sites, making the infestation worse.

The fix: bait that travels home

Bait works where spraying fails. Workers feed on a slow-acting sweet bait, then carry it all the way home to the queens and brood. The GotchaPest Reusable Ant Bait Station is ideal for Argentine ants — they're prolific trail-makers and love sweet bait. Place the station across the trail and let the workers do the delivery run to the colony. You'll see more ants at first, then a drop-off over 1–2 weeks as the supercolony collapses.

Protecting New Zealand

Argentine ants are a recognised invasive species in NZ. They displace native ants and other insects, infest homes and food premises in huge numbers, and "farm" aphids and scale insects for honeydew. If you suspect a new infestation outside a known area, report it to your local council biosecurity team to help track and slow the spread.