Spraying visible ants kills foragers and leaves the colony, and with some species it splits the nest in two. The job starts with identifying which ant you have. Coastal brown ants, the ones pushing sand up between pavers and along path edges, want a protein bait. Black house ants take a sweet gel. Argentine ants run supercolonies across several properties at once.
Sandy soils across the peninsula suit coastal browns particularly well, and the newer estates at Curlewis, Drysdale and Leopold add disturbed ground and fresh landscaping on top of that. It is why so many people here have worked through three supermarket baits and got nowhere: the shop products are sweet gels aimed at the wrong species.