Cottonmouths and Copperheads aren't just aggressive, they're down right MEAN! One of my nephews killed a 5' 1" Copperhead a couple of months ago after it bit his dog. The snake is bigger than it looks in the pic, my nephew is 6' 4" and the dog probably weighs 80-90lbs. He ended up killing 5 or 6 of these things in a 2 week period!Thankfully, most of them would rather run. I've heard that copperheads and cottonmouths can be more aggressive though. I remember one guy took out two big copperheads that were striking at his tractor. They didn't duck when they went under the bushhog.