Just did our pantry, found a hole in the wall back there...
a mouse can squeeze thru a hole if it can get just it's head thru.
It smells like a pungent spice, slightly unpleasant.
But you may have a nest in the wall.. or maybe I do too.
I'm going to scrub the clean pantry with a solution of 6 ounces of white vinegar in 32 oz of water. Then the odor will go down, per the university expert.