The Central West NSW mouse problem has eased over winter, but an expert has warned there's a very real possibility of numbers escalating to plague proportions again as the weather warms up.
"They breed so quickly. You can go from having a few mice around to having a major problem really fast," CSIRO mouse expert Steve Henry said.
"It will be interesting to see what happens over the next month to eight weeks in terms of breeding."
In June, the CSIRO warned of the possibility a two-year plague, in which mouse numbers plateau through the winter, and then pick up again in spring, pushing the plague into a second year until numbers eventually crash.
With the second spring now underway, scientists are keeping a close eye on mouse numbers.
Mr Henry recently visited Western parts of the state including Coonamble, Walgett and Trangie, to monitor the situation.
"While generally there were reports of low numbers - and we couldn't find very much sign of mice, there are the odd patches around the place where people are reporting numbers.
"That would be moderate numbers, but they're still there in patches."
Mr Henry said there was a real chance the wet November the region had experienced could precede another explosion in the mouse population.
"I think the November of 2010 was really, really wet and then we had huge numbers of mice throughout 2011. I'm not saying that will happen this year but certainly it's a similar scenario," he said.
The floods being seen in some areas of the state will "check numbers significantly," but it would only be a temporary setback.
"If you think about this year, just prior to Easter there was a major rainfall event.
"After that I was out talking to farmers and when I asked them if the rainfall event had killed all their mice, their answer was, well, it had set them back but shortly after it had started to dry out they were back in business.
"As soon as the crops dried out again they were back into it.
"They're an incredibly resilient species and while the wet weather will knock things around a little bit we're still saying we need to keep looking."
Farmers needed to remain vigilant, he said.
"While there's not much they can do now, because it's too close to harvest to be baiting, the key messages are: harvest clean so you don't leave any food behind and continue to monitor those stubbles where you have had some grain loss so that mice aren't present and a problem when you sow the next crop next April."
Mouse sightings can be recorded on the Mouse Alert website.