As for an improvement, I'd like to see them show a few more human traits though, like climbing. If that hunger is so strong, they'll climb a fence.
They do that already, as seen in "Guts,"
when Rick was shooting zombies trying to climb the fence in hot pursuit.
Oh yeah... right, in season one, the episode after they climb the tank, but by season 3 they're just kind of hanging around the prison fences
That threat should be bigger at the prison