During the day, Graham Jones’s grain shed in Tullamore in central New South Wales seems normal enough.
A bounce-back harvest following years of drought means he has almost 3,000 tonnes of wheat stored.
But at night time, the mice move in.
They pour in and out of the shed, funneling into one of his large traps, which quickly captures hundreds of the rodents.
Mr Jones says the mice arrived in February, and haven’t shown any signs of leaving.
“Because we had such a good season, we were full to the brim everywhere, and we put hay in front of the sheds to hold the excess grain in, get the extra couple of loads in,” he says.
“And when the mice came we thought they’d go, and they didn’t.
Mr Jones says the local silos weren’t running during harvest for financial reasons, leaving him with no other option but to bag up his excess grain and store it in his paddocks.
This left a source of food for mice to gather around and is now preventing him from sowing his winter crops, because the animals can eat the seeds before they even have a chance to grow.
Signs of mice can be found throughout his property, from old pianos to the bottom of wheat augers that slowly fill with dead mice and need to be pumped out.
Despite the delays and damage from the mice, Mr Jones says he’d take a mouse plague over years battling drought any day.
“We’re a lot more optimistic than what we were a year ago, things were pretty down and out then, but at least we’ve got something to sow now,” he says.
How mice damage could affect the next drought
Further north on Adam Macrae’s farm near the town of Coonamble, there is less optimism.
He has been left with a damage bill in the hundreds of thousands of dollars after mice ate through upwards of 1,500 bales of hay and straw.
“It was nearly overnight when they just arrived in big numbers and we started baiting, baiting twice a week, around the hay bales,” he says.
“And they kept going and going, and they’ve done a lot of damage.”
Mice can give birth to a litter of up to 10 offspring every 20 days, and can fall pregnant as soon as they’ve given birth.
Mr Macrae says the bales were invaluable insurance against the next drought, and the true impact of their loss won’t be felt for years to come.
“We’re lucky enough to be having a good season now, but when the rain stops falling, that’s when we’re really going to feel the pinch of not having the fruits of our labour around us.”
The NSW government recently announced its pledge of $50 million towards free bait and grain treatment for mice-affected farmers, in addition to other supportive measures.
For farmers like Mr Macrae though, the damage is done.
“Some guys will talk about it, some guys won’t,” he says.
“I know plenty of guys who have lost in the order of thousands of bales, and that’s a lot to take out of the system for the next drought.”
How long will the mice stick around?
CSIRO Researcher Officer Steve Henry is travelling through New South Wales gathering evidence of the damage and giving seminars to threatened farmers.
He says the scale of the plague is hard to quantify, but that communities like Coonamble have been hit hard.
“That was completely contaminated and so the farmers were only left with the option of burning that hay. That was a $120,000 loss on one farm.”
Mr Henry says if farmers aren’t able to contain numbers by the end of winter, a fierce reprisal is likely later in the year.
“If we get a high level of survival of mice over winter, then if conditions are favourable next Spring, then they’ll start breeding early from a high population base,” he says.
“And that leads to a very rapid rate of increase.”
How will the mice affect this season’s crop?
To the state’s south in the community of Parkes, farmer Rob MacGregor says he thought he’d missed the worst of the mice until recently.
Weeks later, after extensively baiting his property and keeping a close eye on the mice, Mr MacGregor says he made the call to start sowing wheat and canola.
But the fear of the mice returning to his property is still present.
“It’s not a case of the damage they’ve done, although they are doing damage,” he says.