Quoted from Whysnow:May be indicative to a mouse nesting up in the game when it was in the BARn. I had a game shipped in and the previous owner had no idea that a mouse family had taken up residence in the backbox. In shipping the stored seed and hay from the nest was shaken loose and was a fun surprise when I opened the game.
Given the sellers lack of attention to detail I would not be amazed if he also did not notice a mouse nest in the game...
You have a great imagination.