How to get rid of ants: why spraying makes it worse, and what works

Ants are the pest people fight longest with the least to show for it. You can kill a bench-top trail every morning for a year and change nothing, because the trail isn't the problem — it's the visible 5% of a colony that may hold hundreds of thousands of insects, safely underground or in a wall void, producing replacements faster than you can wipe them away. Control means reaching the colony. Here's how that works.

The trail is not the problem

Worker ants follow pheromone highways between the nest and food. Kill the workers and the colony promotes more; wash the trail and scouts re-map it within days. The queen — or queens; some species run dozens — never leaves the nest. Everything that follows comes down to one principle: make the workers carry the control back to the queen, instead of killing the messengers.

Melbourne's usual suspects

Black house ants — the small dark kitchen ants, sugar-obsessed, nesting in wall voids and under paths. Coastal brown ants — the ones excavating little soil piles between pavers; protein-feeders that make multi-queen super-colonies, and the hardest to beat with retail products. Argentine ants — invasive, massive interconnected colonies, notorious for re-invading treated houses from next door. Bull ants — the big aggressive ones with a genuinely painful sting; a lawn-and-garden hazard rather than a kitchen pest. Species determines bait choice — sugar baits do nothing for a protein-feeding species — which is why identification comes first on a professional job.

Why spraying can make it worse

Repellent surface sprays don't just fail against the colony — several common species respond to spray stress by budding: the colony splits, queens disperse, and one nest becomes three. It's the ant equivalent of kicking a dandelion. Spray also lays down a barrier that stops ants reaching baits, sabotaging the one method that does reach the queen. If you remember one thing: never spray near a bait placement.

What actually works

Baiting. Slow-acting baits matched to the species' current appetite get carried home, shared, and fed to larvae and queens — the colony declines from the inside over one to three weeks. Patience is part of the method: for the first days a good bait makes the trail busier, which is the point. Hygiene runs support: wipe trails with detergent (erases the pheromone map), seal the food they came for, fix dripping taps — ants need water as much as sugar. Sealing entry cracks around windows, doors and pipe penetrations turns down the pressure permanently.

The outside game

Most kitchen ant problems are garden colonies commuting. Nests live under paths and pavers, along fence lines, in mulch against the house, in retaining walls. A professional treatment works the outside: locating nests, treating them directly, applying a non-repellent barrier the ants can't detect (they walk through it and carry it home), and baiting the routes. Non-repellent chemistry is the big professional advantage — colonies collapse instead of scattering.

When to call a professional

Call when baiting hasn't cleared it in three to four weeks, when ants persist through winter (that's an indoor wall-void nest), when soil keeps appearing between pavers (coastal browns — retail products rarely finish them), or when it's a food business, where an ant trail is an audit finding. A professional ant treatment combines identification, direct nest treatment, non-repellent barriers and baiting in one visit — with the documentation that audited sites need. One treatment typically holds for many months, and fixing it in spring beats fighting the summer surge.

Frequently asked questions

What gets rid of ants permanently?

Reaching the queen — slow-acting baits carried into the nest, direct nest treatment, and non-repellent barriers. Surface sprays only kill workers, and several species respond to spraying by splitting into multiple colonies.

Why do ants keep coming back after I spray?

The colony — including the queen — never contacted the spray. Workers are replaceable; some species even bud into new colonies under spray stress. Baits beat sprays because ants deliver the treatment home themselves.

Why are there more ants after I put bait down?

That's the bait working. A well-matched bait recruits heavy feeding for a few days while it circulates through the colony. Numbers climb, then collapse — killing the feeders early defeats the method.

What are the tiny black ants in my kitchen?

Usually black house ants chasing sugar and water, nesting in a wall void or under a path outside. A sugar-based bait plus sealing their entry crack usually clears them — if they persist through winter, the nest is inside the structure.

Are ants in the house a health problem?

They can be — ants trail across bins, drains and benches indiscriminately and can transfer bacteria to food surfaces, and in food businesses they're a compliance breach. Bull ants are a different issue: a painful sting and real risk for anyone allergic.

A1 Pest & Weed Control handles this for homes and businesses across Melbourne — licensed technicians, guaranteed results, and fast response: 0411 859 516 or get a free quote.