Well, while not in a such sophisticated device like a printer, but also not so small like a mouse: in April one year, just as I was about to open the grilling season (Midwest), I pulled out the bin under the grill, devised to store a bag of coal, etc, to find this:
Also. for years, my cat would jump on the printer table the moment I begin printing, walk around it sniffing, then settle into a pounce-ready position, waiting for something to come out. Disappointed every time.