fuel line issues

Own 2003 Four Winds 5000 28a. Went camping last month. Pulled into lot to use swimming pool. When exiting the rig, I noticed gas coming out all over. Used the ever famous duck tape and drove to an rv mechanic. He said the fuel line blew, had part, fixed it and away we went. Said it is very likely that a squirrel, or some rodent ate through the line. Two days ago, went to where we have rv stored, with intention of taking to my rv mechanic to seal leak in window which he did 3 months ago. While traveling there, same thing happened. Gas was everywhere. However, I was able to drive to the rv place because it was so close to where we store the rv. He is now replacing the fuel line part above the gas tank. Question. Is it possible that a squirrel or rodent could be doing that? I have been putting mothballs under the rig which was suggested to me. Why don't they provide copper or some kind of metal for the fuel line if a rodent is causing that problem. I will state that we purchased this 2003 one year ago, and could it be possible that the fuel line was on the border of blowing?
Any suggestions or comments would be greatly appreciated. We love our Class C and already are booked to go next week and camp at a state park for 10 days.
Michael