Rodent ingress to properties.
Rodents don't just walk and swim they are good climbers also.
During the winter months rodents will look for harbourage areas were they can stay out the cold, places like under/inside sheds and in the loft space of properties in the loft insulation to stay warm this in turn can use a range of problems.
But… there are ways of preventing them from occurring in the first place, when it comes to your property the areas of ingress can stem from broken air bricks, holes in wall, gaps around waste pipes, plants growing to the top of roofs. These are just a few but it is always a good idea to have a quick look before winter sets in to make sure you are free of potential ingress points.