De Pere, WI Public Health Rules: Rodent Control (2026)

Section 74-7 of the De Pere Code of Ordinances makes rat control a standing property maintenance duty. All business buildings, defined broadly to include stores, restaurants, warehouses, factories, and any structure where food is stored or animals are kept, must be ratproofed, freed of rats, and kept in a ratproof, rat-free condition. Residential buildings must be kept rat-free and, if necessary, ratproofed as well. When the health officer sends written notice identifying a building that needs ratproofing, the owner must start work immediately and finish within the time stated in the notice, which cannot be less than 15 days, or face being deemed guilty of an offense under the section.

If the health officer instead notifies an occupant of active rat infestation, eradication measures must begin immediately and continue until the health officer declares the premises rat-free; waiting more than five days to start is itself a violation. The health officer can make unannounced inspections, and where conditions inside an occupied business building create extensive rat harborage, the health officer can close the building entirely, post a placard reading it is closed to human habitation, occupancy or use, and keep it closed until ratproofing and harborage removal are complete.

Section 74-7(k) also sets minimum ratproofing construction specs, like 18-gauge perforated sheet metal and half-inch maximum foundation vent openings, that new construction and remodeling must meet.