I just shoveled a possum that attacked my old layer. She cried so loudly... and when I saw her, I thought she was dead, so I hit the possum with a stick that did not make him budge. Eventually, I took a long spade and hit him hard.. still he did not budge.. when I left to pick something, I heard my layer screamed again.. she still alive.. strong old girl! I caught her and put her at another site.. *I don't own a gun or anything like that except for BB gun* Then, I proceeded to smack that possum.. Now, I realized it's very difficult to really kill a possum.. Finally, he climbed out of the chicken run hurting as I smacked his head with the spade or shovel... Anyway, I heard that ammonia can deter the possum.. Is this true? Has anyone try this before? I put a few bottles of ammonia around the chicken house, and the house is under lock-down now..