Mice and rats are opportunists, and Monongahela properties give them plenty of opportunity. Housing here dates heavily to the early-1900s steel boom, with narrow lots and full basements standard. Once inside a wall void or attic space, they're difficult to remove without sealing the entry point that let them in.
Exclusion is the core of effective rodent control: finding and sealing every gap a mouse or rat could use to get inside, since traps alone just remove the current population without stopping the next one. We pair exterior sealing with interior trapping or bait stations, then follow up to confirm the problem is resolved.