Mice living in unfavourable seasonal conditions may have a shorter breeding period, while those with nests and good cover are likely to have an extended breeding period. Research suggests that it is the quality more than the quantity of food that extends the breeding season. A mice plague is a natural event; in a similar way all plagues eventually come to an end. Wet and cold weather force the mice into stacks of hay, it also makes them less active, upsets their breeding cycle and causes disease.
