Cabin filter rat nest

Another view

 

Looks like there is enough room where the notch is cut for a meese to squeeze thru. You might want to gob some silicon on it.

 

A mouse can fit thru a hole that's the diameter of your finger. I had one get into my cab thru the cabin air intake- it pushed down the cabin air filter which is amazing determination for a tiny animal. I added a piece of expanded metal over the opening similar to what's shown above.

 

I may be wrong but isn't there a button on the dash to close fresh air vent and go recirculation only?
1st gens have SS screen under cowl and vent/recirc. button.

 

Yes and you’d have to remember to turn it to recirc every time. If I’m not mistaken the door is vacuum controlled and mine stayed open overnight while I was doing the screen install. I’ve had mice get in before and build a nest on top of cabin air filter. Since that I’ve got an outdoor Tom cat that kills all mice and rats. I also use a poison called just one bite, and now this screen. This 3 pronged approach should work. Time will tell