The answer to 'why do I have mouse' is that mice are common household pests that can invade your home in search of food, water, and shelter. Mice are attracted to crumbs, spills, and accessible food sources, and they can squeeze through very small openings to get inside. Signs of a mouse problem include droppings, gnaw marks, and hearing scurrying noises at night.
To get rid of mice, it's important to identify and seal up any entry points, remove food sources, and use humane traps or repellents. If the infestation is severe or you're unable to get it under control, it's best to call a professional pest control technician who can properly inspect, treat, and prevent future mouse problems.