The best way to keep rodents from entering your home is to replace your shingle tiles before they get old and brittle. This allows rodents to lift the shingles and chew thru the wood decking. The other point of entry is from the perimeter of the roof where the eves trough meets the roof. Usually there is a void between the plywood and the decking and the fascia board is. Rodents will sometime enter thru this space. Installing a metal drip flashing at the perimeter of roof with enclose this gap with metal drip flashing. Be sure to use a heavy gauge steel and not aluminum stock as squirrels can chew thru aluminum quite easily.
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