The answer to 'why is my mouse swarms' is that a mouse infestation is typically caused by an abundance of food, water, and shelter in or around your home. Mice are attracted to homes that provide these essential resources, leading to rapid population growth and multiple mice sightings.
Common signs of a mouse infestation include droppings, gnaw marks, nests, and hearing scurrying noises. Mice can reproduce quickly, with females giving birth to 5-10 pups every 3 weeks. If left untreated, a small mouse problem can quickly turn into a swarm.