More rats up north, fewer mice in south

When cane growers in the north Queensland farming town of Ingham noticed their crops suddenly started falling over, they knew they had a serious problem on their hands.

It was bad enough that many plants couldn't be harvested because they were isolated by heavy rain, but then rats came and chewed through what was left.

The combination of water, rats and increased farming costs has led to what's been described as one of the worst years for the district in recent memory.

Ingham canegrower Michael Reinaudo believes about 15 per cent of his crop has been destroyed, which he estimates could be worth up to $250,000.

"It's gut-wrenching," Mr Reinaudo told AAP.

"There's a lot of factors and this is just another thing that we need to deal with."

There are concerns the problem could worsen next harvesting season as many crops are still in paddocks and the impacted area is so vast baiting needs to be done by helicopter.

Fellow canegrower Carol Mackee also lives in Ingham and her crops have so far been spared, but she said the rodents have had a major impact on the community's wellbeing.

"People are really depressed and when you get depression setting in the whole town gets depressed," Ms Mackee said.

"It's not nice. This is one of the worst years we think we've had for quite some time."

It's a different story south of the border in NSW, where flooding rain that caused so much pain in 2022 may also have brought relief from mice.

A research team will soon assess numbers in central parts of the state but CSIRO scientist Steve Henry said early indications show the floods may have wiped out some of the rodents.

"When they were having babies through the spring and that really wet period of time ... most of those young animals will have drowned because they couldn't get out of the burrow," Mr Henry said.

NSW Farmers president Xavier Martin said a reduction in mouse activity in his state was a positive after a tough six months.

The last mouse plague left the NSW farmer with tens of thousands of dollars worth of damage to his house while the losses in the paddock ran into the hundreds of thousands.

"It would be great if the conditions that damaged crops and livelihoods also mitigated the build-up of mice in a really difficult year," Mr Martin said.

"Farmers must remain alert to mouse activity and rely on the science behind risk management and responses when it comes to mice," he said.

Mr Henry said while numbers will be low in NSW, South Australia and western Victoria could face challenges because grain was left behind after good harvests.

A research team trapping on the Adelaide plains has reported a lot of active burrows in the area with pregnant females.

Mr Henry urged farmers to take stock and do what they could to prevent outbreaks while they still had the opportunity to do so.