if your dnr isnt doing anything about it,talk to them about it and if it comes to it try starting a pettition because its their JOB to take care of stuff like that.

also, if your laws/regulations say that u can ONLY shoot them in season, try getting a permit to hunt them on your land, but most likely you can shoot them legally on your land as a varmit...but u cant do nething with thim after they die.

and the most obvious solution....SHOOT THE SOB'S 24/7