A new from factory AD cab allows mice to enter because it’s “the cab that breathes”
Mice can fit through the parking brake hole in early cabs
But also through the A Pilar bottom drain vent hole on all cabs
Then they climb up and pop out high under dash
To stop these openings I use stainless steel wool in the bottom of the pillars under the lower door hinges and I made custom better fitting floor sponge seal supports out of metal that sit ontop the transmission
There are also two drain vent holes on the back corners of the cab but these seem perhaps just small enough maybe mice can’t get in there, but more stainless steel wool can’t hurt much
So far the mice can’t get into my 1950 now but they are rampant in everything else.
-s