Millions of mice have invaded farms and towns from Queensland to South Australia, threatening next season's grain harvest.
Extensive damage is reported to rice crops in the Riverina Murray region of south western New South Wales.
The ABC reports the harvest is forecast to be around 800,000 tonnes - triple the output last year after years of drought. But it's now being threatened.
South Australian MP Adrian Pederick, says some farmers will spend up to $A70,000 on bait this season.
He says regional bait mixing centres are needed to save farmers money on commercial bait.
In the Riverland and Mallee region, Loxton Waikerie Mayor Leon Stasinowsky says the mice are moving into towns from farms.