Mice, rats, and other rodents like raccoon, possum, and squirrels can cause major damage to ducts in attics and even cause thousands in damage to car engines.   They can find their way into our homes and businesses through very small openings along pipes, improperly sealed doors, attics, roof vents, etc. Keeping them outside of your home is a process in which all possible openings get sealed up.  Keeping your home free and clean of food sources and maintaining the right bait stations around the property will reduce the amount of rodent activity outside your home.