Pissing mice! Great insight and I've never seen it mentioned before. I'll bet that's a much bigger problem than generally recognized.
As mentioned above, I recently had the Pro Logic section of a 9 year old Parasound preprocessor die for no apparent reason. When I went back to check (entire system built into wall) I found lots of mouse home decorating residue (although no obvious "stains").
The Parasound was the highest component in the stack, just below the ventilation holes in the custom cabinetry. Mebbe coincidence, mebbe not......
Anyway, I am now rearranging the stack so that the cheapest component (a VCR) is on top. I guess we need a rodent section in all the HT FAQ's.
-- Mike
Edit: As an afterthought -- I just had a mental image. As I said, I have a line of circular (ventilation) holes in the wooden platform just above the left equipment stack, and I have found the nest of a mouse family nearby. I have this mental image of this mouse family leaving their little nest to go to their little "multi-holer" outdoor privy, then returning, releaved.
But then I have an active imagination.