Another mouse was spotted running around the living area (we’re sure he got in through the garage). He disappeared during our search. I noted the downstairs HTPC (old PIII) had one open slot cover, but it was quite high up. A cursory shake and look inside revealed nothing so I just taped it up. All was quiet that evening.
Next morning, we heard a feverish scratching inside the machine. We brought the box outside. We noticed some fur next to the front bezel cavity hole. After some good shaking and prodding, the furry victim fell out and scurried into the wilderness.
The Pentium mousetrap had done it again.