The best permanent rodent exclusion materials for San Diego homes include sheet metal, galvanized hardware cloth

https://westusa2.blob.core.windows.net/home-fix-hub/what-san-diego-homeowners-should-do-about-roof-rats.html

The best permanent rodent exclusion materials for San Diego homes include sheet metal, galvanized hardware cloth, copper mesh, stainless steel mesh or wool, cement, and caulk for sealing gnaw-prone gaps.