The largest pile that I have seen was about the volume of a 5 gallon bucket, standing conical in shape. No serious smell. I was thinking bear, an empty bear. I did not see what deposited the pile. Track less area, very hard compacted dirt. I can't remember the time of year. We have American Skunk Cabbage that bears eat the roots as a laxative when they become active late winter/early spring. Cleans them out. Only pearl of wisdom that I can add is to never over trust a fart. I will monitor for double-cheek lifters.