Not an expert on downunder insects, but those are a species of paper-wasps which are agressive stingers. Make sure you know exactly where the nest is located, wait until late at night (wasps do not fly at night, they all return to the nest) get a couple of cans of jet-stream spray (most spray 6m or more) wasp killer and using both at once spray and soak the entire nest. If you do not get all do it again the next night,