With the weather being mostly what one would expect in winter, the warmest places to be if you're out and about in the country is indoors.
That’s what the mice think like too. And as has been noted before the wee blighters bring disease with them into mushroom houses.
Advisors recommend that growers should take every measure to ensure that the pesky rodents do not manage to create a SNAFU and blight their produce with disease.
Stalker reckons that the cat comes into its own in usefulness on this score, but using any method that works is advised.