The answer to 'mouse trails' is that mouse trails are the visible paths or tracks left behind by mice as they move around your home. These trails are usually made up of dirt, grease, and other debris that mice pick up as they travel along the same routes repeatedly.
Common causes of mouse trails include mice seeking food, nesting materials, or shelter. Trails are usually found along baseboards, behind appliances, and in other tight spaces where mice frequently travel. Seeing mouse trails is an indication that you have an active mouse infestation and should take action to address it.