I was told that ants breathe through their feet. If you put something like Comet cleanser with bleach on the ground where the ants go, it will kill them. We use it here in the states and it is great. Don't know if you have anything like that in Australia but you can google Comet cleanser and see what it is similiar to over there. It kills fire ants in Texas and I won't travel there anymore without it. DH almost got ate up alive when he went to hook up the hose to the water hydrant, learned about fire ants in a hurry then. Good Luck.