Update!!! There is a groundhog/woodchuck living under my shed that is approximately 50 feet behind my house. I've been told that it has had to have been living under it for atleast a year as neighbors have said they have spotted it in my yard. My daughter-in-law saw it yesterday and snapped a pic. I do not know how to place photos on to sites otherwise I would show you what it looks like. After seeing the photo I looked up on the computer for other pics of groundhogs and it definately was a match. I guess my next step is to call an agency to humanely remove it and transfer to the woods somewhere. Then I will have to call some one to come over and look at my foundation. I have no idea how I will be able to move the wooden shed to fill the holes that I am sure are under it. Thanks to those who responded to my original post.