Guards and screens shall be supplied for protection against rodents and insects. All basement or cellar windows which are openable shall be supported with corrosion-resistant, rodent-proof shields of not less than No. 22 galvanized sheet gage (0.034") perforated steel sheets, or No. 20 B&S gage sheet aluminum, or No. 16 steel wire gage (0.063") expanded metal or wire mesh screens with not more than one-half inch mesh openings, or with other material affording equivalent protection against the entering of rodents, including storm windows. (Ord. 1977-14 § 6-11, 1977)