They're called yellow crazy ants - but it's the poor Pacific Island villagers they're terrorising who are being driven around the bend.

Now, a team of Kiwi scientists are turning exterminators to rid the hated little pests from islands in Tokelau and Kiribati.

Yellow crazy ants, regarded as one of the world's 100 worst invasive species, are distinguished by their slender, yellow to brownish body, very long legs and, hence their name, an erratic walking style.

Most unpleasantly, they have a tendency to spray formic acid when disturbed and are capable of mass attacking and killing larger animals.

While the ants are not known to be established in New Zealand, the species is found throughout the Pacific and on Christmas Island, and are commonly transported inside sea cargo.

Recognising the threat they pose to the Pacific region, Kiwi scientists have recently stepped up efforts to combat them.

Around 10 years ago, Professor Phil Lester of Victoria University was asked by villagers to help combat infestations on two of Tokelau's three atolls.

In 2011, Professor Lester and his colleagues were told the ants had spread to the third atoll and were causing damage and disrupting to the lives and local people.

And while doing some separate work in Kiribati, researchers discovered the yellow crazy ant there as well.

Victoria University's Dr Monica Gruber, who has been researching invasive ants in the Pacific region since 2008 and is now heading a collaborative effort targeting them, said the ants could become "massively abundant and widespread".

"People tell us they are unable to sleep due to ants crawling over them, crop production is reduced, and pets and livestock are affected by ants spraying acid in their eyes."

Despite the huge impact of these pests, many communities were unable to do anything to manage the ant populations because they could not afford pesticides or other methods of ant control, she said.

With the assistance of Victoria University's commercialisation office, Viclink, Dr Gruber and Professor Lester formed a non-profit entity called Pacific Biosecurity, which has been boosted by a $1.5 million contract from the Government-managed New Zealand Aid Programme to help improve resources for ant management and biosecurity across the Pacific.

Across the region, Pacific Biosecurity's goal is to help prevent the spread of species like the little fire ant.

"These tiny ants have an extremely painful sting, and the effects of the ants can be serious when they are in high abundance," Dr Gruber said."In some places, the ants have forced people off their land as they can't tend crops."

Because they were found on both sides of the Pacific, there was an urgent need to stop their spread into the rest of the region, and improve the ability to manage them."Prevention requires less effort and resources than eradication - which becomes impossible when these ants cover a large area.

"That's why we need to focus on biosecurity across the whole Pacific region to prevent the ants - and other invasive species - from spreading."


-by Dr Monica.Gruber