The answer to 'why is my mouse invasion' is that mice are common household pests that can find their way into homes in search of food, shelter, and warmth. Mice are attracted to crumbs, spills, and improperly stored food, and they can squeeze through very small openings to gain entry. Signs of a mouse invasion include droppings, gnaw marks, and noises in the walls or attic.
To solve a mouse problem, you'll need to identify and seal any entry points, remove food sources, and use traps or other deterrents. DIY methods can be effective for minor infestations, but for larger or persistent problems, it's best to call in a professional pest control technician who can safely and effectively eliminate the mice and prevent future invasions.