RE: getting rid of beaver (trapping beaver)
A drown set with a number 3 double long spring trap will do the trick. You can do it as a "blind set" using beaver castor (available at trapping supply outlets). Another option is to tear a small hole in the dam, then set the trap under water in the hole. Beaver will get caught when they start trying to repair the damage. Either way, you need to use a good drowning set with a cable and "brake," or the beaver will chew or twist their foot off and get out.