Spraying the ants you can see kills foragers and leaves the colony intact, and with some species it splits the nest into two. The job starts with working out which ant you have. Black house ants take a sweet gel. Coastal brown ants, the ones pushing sand up between pavers and along driveway edges, want a protein bait. Argentine ants run supercolonies across whole streets.
Armstrong Creek, Charlemont and Mount Duneed are the heaviest ant postcodes on this side of Geelong, and it is not bad luck. Disturbed ground, fresh landscaping, new paving and irrigated garden beds on former farmland is close to ideal habitat, which is why supermarket baits keep doing nothing in those estates. Numbers drop in a day or two and keep falling across the week.