Patching Large Holes in Sheathing

[pharper]

I'm in the middle of adding an exterior door, electrical and insulation to my garage. I discovered several large gaps in the sheathing where mice and possibly other vermin had gotten into two of the stud cavities. What's the easiest/best way to patch these? Could I use aluminum flashing, or is there anything better? I plan on spraying foam in smaller seams to prevent infiltration.

 

[BlindViper]

Looks like its georgia pacfic tar board. Id cut 1/2 plywood and overlay the holes and use the shortest screws to get it to hold.

 

[pharper]

Looks like its georgia pacfic tar board. Id cut 1/2 plywood and overlay the holes and use the shortest screws to get it to hold.

That worked great for the large hole where I had something to fasten the plywood. Now, how should I fasten elsewhere? I might be able to get away with some expanding foam for the long gaps at the bottom about 1" wide.