Hounds Man is right. Your best bet is to call an A.D.C. trapper. I am by no means a mechanic and if I try to fix my own rigs when something on them needs fixing, I'll screw it up worse than it was. It's basicly the same thing with your beaver problem. Belive me when I say the worst thing I can here on my job is when I get to the site the land/home owner says "I've tried everything I could think of to get rid of these things but their still here!" Now I,am looking at a job that should take maybe two or three days instead may take three weeks. My advice....call a professional and let him handle it. Even if it costs you a few bucks you,ll be money ahead in the long run.