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

https://kameronumbm236.rivetgarden.com/posts/common-entry-points-rodents-use-to-get-under-san-diego-homes

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.