There was plenty of food in paddocks after a record harvest and fewer sheep to clean the spilt grain and stomp on their nests.And then some summer rain fell, providing mice with drinking water and milder temperatures.Mice typically live everywhere humans do, but often in low numbers, so they're not always seen.When they build to plague levels, there's no escaping them.Some towns in Western Australia, such as Northampton and Morawa, have mice infestations in their public buildings and homes It is yet to be seen if travellers change their plans.Mouse plagues typically end due to a combination of factors, including food shortages, disease and cold weather.Once farmers spread the more effective baits on their paddocks, they should see a reduction in numbers within hours.But Mr Henry warns the bait can only be used on farms, not in urban areas, and while it will have an impact, it's not a "silver bullet" for the problem.Mice may stop moving en masse out of the paddocks into houses and buildings, but they'll still need to be removed from the areas they're inhabiting now.Residents will need to keep trapping and baiting the vermin.