I've been looking for some sort of Scientific forum to post this in to see if I can get some sort of person who knows a lot about animals to help. It doesn't seem quite right for the "Biology" section - so I'll try posting in here. My friend sent me this picture: "Okay, my cat kills rats and mice all the time, but I'm pretty sure this isn't one. Rats/mice have hairless tails, and this thing has a furry black tail, and it's about twice as big as anything else my cat has killed." At first I thought it was a Mink or a Muskrat, but I'm pretty stumped. He lives in Michigan. Any help would be appreciated. Thanks!