As you enter each apartment, inspect the wall around the door for signs of rodents and rodent entry points. You are looking for droppings, gnawing damage, entrance holes, rub marks, nest material and hoarded food. Move clockwise through the account, inspecting walls, and checking closets and cabinets as you come to them. Do this for each room.
After checking the walls in each room, check the floor, including anything on or touching the floor (i.e., furniture, appliances, etc.). Inspect drop ceilings.
Spend extra time in the kitchen. Have the stove and refrigerator pulled away from walls and check underneath. Sweep or vacuum up any droppings and nest material so that future activity can be identified. Pay special attention to back corners of lower cabinets, pipe openings under sinks and stove pan drawers.
Check the utility closet and openings around vents and lines, which can be major entry points for mice. Make sure you can access locked utility closets.
Once mice are out of control at a property, treating them as you find them on your regular service visits won’t cut it. One good approach for heavily infested garden apartments is to treat blocks of contiguous (touching) buildings, not just apartment units, and not just apartments in a single-entry address.
Mouse control service and mouse-proofing are performed on all the units in a block of apartment buildings at the same time. This strategy minimizes the risk that mice in an untreated building will move back through the voids and conduits to repopulate the treated building that it touches. Scheduling must include re-inspection, and re-servicing as necessary, in every unit in the building block, until there is no further evidence of mouse activity in the entire block of buildings. — Sandra Kraft and Larry Pint