I'm pretty sure it was racoons. Visitors to the Fort need to make sure they secure their garbage at night. It needs to be put in a trash can with a lid or taken to a dumpster located in most loops. As in my second picture, a visitor has laid another bag of garbage by the can. Not sure why they did not put it in the can. I know it is not full because right before this was put there, I put ours in the can. Visitors need to be more responsible. After the "racoons" statement, the rest is just my opinion.