They are bad news! The only way to stop these guys will be a biological attack of some description :?
Hopefully more of our native funa will adapt to working them out, or just simply avoiding them :? I know that crows have worked out what parts can be eaten and what parts can't, and I've also heard the stories about some blacksnakes adapting with size changes in relation to dealing with toads. These things are a damned catastrophe! Something really has to be done, and a hell of a lot faster than the rate it's going!