choochee

Looking for some help from anyone who has familiarity with where the "air intake" for the can air conditioner/heater might be?.....I keep getting mice behind the "blower motor" and I have no idea how they get in there and was hoping someone might have some ideas....I've been working on my van FOREVER and I just don't want to ever have to deal with mice again... I've attached a few pictures...Any help would be MOST APPRECIATED - Choochee

Are you the person who came up to say hello to me in my 4x4 Van in the Shaws parking lot?