Gaps like this one around a dryer vent hose in the basement need to be sealed properly to prevent mice from entering the structure. This gap is so large you can feel a heavy air current coming thru the foundation. This is the first step to preventing your home from getting infested with mice or other pests. Exclusion for mice is a service we offer and works well when paired with a rodent maintenance plan. Call or go online today to schedule a no charge general pest inspection.