Roy Hamilton, who runs a property between Rand and Urana in NSW's Riverina, with his wife, son and daughter-in-law, says mice are making their presence felt.

"We've spent close to $1000 domestically on baits just for around the house and sheds," Mr Hamilton said.

"The swimming pool has been a good indicator.

"I pull 20 to 40 out a night.

"In our house and my son and daughter-in-law's place we've just got traps going off all night.

"You can empty and set the traps before you have tea and you'll be emptying them all again after tea."

Mr Hamilton said mice were even causing problems in the bedroom.

"We had a funny one the other night," he laughed.

"My wife kept hitting me on the shoulder and telling me to turn my bedside light off and I thought I did.

"I woke up about an hour later and it was on again and she clocked me again and told me to turn the bloody thing off which I thought I did.

"So, as you do when you can't get to sleep, I was looking at my phone and the lamp came on again.

"It's one of those lamps that has a pressure switch on the top of it and the mice were climbing up the chord and running across the top of it and turning it on."

IN OTHER NEWS:

While the Rand and Urana-based farmer believes mice have started to slow down domestically, he said land holders were seeing a widespread presence in paddocks.

The main concern for farmers now is ensuring crops planted are able to germinate.

"A really good rain would help flood a few burrows out and probably cause a bit of cold and disease which seems historically to cause them to implode after that kind of stress," he said.

"The populations seem to collapse."

As things stand right now, it's difficult to determine how much damage mice have actually caused with farmers recently sowing crops.

This in itself causes issues because once the damage has become apparent, the optimal time to sow crops may have passed.

"You end up with a sub-prime establishment and if they're too bad obviously you've got to go and re-sow it which isn't ideal," he said.

"It's not only the cost of seed because by the time you realise the damage they've done you're past the optimal time for establishment.

"It can affect the yield out the other end plus the cost of replanting.

"If you've got to go replant a crop you're up to $160 a hectare and you're in a month later than you probably want to be."

Farmers are hoping the mice population doesn't reach a critical mass and hit plague levels.

"You can only try and contain the damage, you can't really stop a mouse plague so we don't know if it will get worse or better, but hopefully it'll get better," Mr Hamilton said.

"It's nine or 10 years ago that we had the last really big one and they're not as significant as they were then in the paddock.

"They've been just as bad in the house, why that happens I don't know."

CSIRO research officer Steve Henry said landholders were seeing higher than expected mice numbers, particularly in fields that experienced grain loss last year.

Although Mr Henry expects the upcoming cold weather to slow down breeding, he warned farmers to remain vigilant.

"We're telling farmers that they need to go out and walk in their paddocks to look for signs of mice," he said.

"It's not good enough to drive through the paddock because they miss signs of mouse activity.

"Numbers are high enough at the moment that we're concerned with the sowing of the winter crop and farmers should be prepared to protect their crop as they sow it by putting out bait."

The CSIRO hope to change the tone of conversation around the idea of a "wave of mice" making its way south from western NSW.

"We're trying to get away from this whole concept that mice move across the landscape in a wave," he said.

"Moving is actually a really dangerous thing to do for a mouse, it puts them at risk of predation, and the only thing that makes them move is running out of food."

A Department of Primary Industries spokesman said he had received feedback from landholders in the area that numbers were down following the recent cold snap and rain.