Ants keep coming back because the trail you wipe or spray is only the foraging workers, while the nest and its queens stay untouched in a wall, a paving edge or a garden bed. You get rid of them for good by finding and treating the colony, not the line on the bench. The Victorian Department of Health's technical note on ants says direct treatment of the nest usually gives the most effective control, and that follow-up treatment may be needed for severe infestations. Book ant control when trails return soon after cleaning, when ants nest inside walls or ceilings, or when they turn up in power points.
Which ants invade Sutherland Shire homes?
Australia has more than 4,000 known ant species, but the technical note says only a handful, mostly introduced, are pests. These are the likely ones on your benchtop:
- Black house ant (Ochetellus glaber): 2.5 to 3 mm, intensely black, strong odour when crushed. Prefers sweet foods and commonly nests in ceilings, cavity walls and subfloors.
- Coastal brown ant (Pheidole megacephala): brown workers of 1.5 to 3 mm with large-headed soldiers. Prefers meat and grease, nests around paths and rockeries, and moves into wall crevices and behind skirtings.
- Argentine ant (Linepithema humile): slender and brown, 1.5 to 3 mm, in well-defined trails up to three or more ants wide. Nests at tree bases, building edges and lawns, moving indoors in wet weather.
- Whitefooted house ant (Technomyrmex albipes): shiny black, 2.8 to 3.5 mm, more active at night, sometimes nesting in wall cavities and behind cupboards.
Species matters because each one feeds and nests differently. A Kurnell home where coastal brown ants nest along the paved back path and trail inside to the pet bowls needs ant control in Kurnell that starts by locating those outdoor nest holes, not another wipe of the laundry floor.
Why do ants keep coming back after you spray?
Ants follow chemical trails. The technical note explains that ants use pheromones to mark routes to food. Wiping the trail removes the scent for a while, but scouts from the same nest soon lay a fresh line.
Spraying the visible trail kills workers, not the queens producing new ones. Several pest species run more than one queen. Argentine ant nests have multiple queens, nests can be interconnected, and the note warns that ants can recolonise from a neighbouring area within two weeks. Whitefooted house ant colonies can bud, sending a reproductive and a group of workers off to start a new colony nearby. Pharaoh's ants should not be sprayed at all, because spraying fragments the colony and tends to worsen the infestation.
So a quiet week after spraying is not a cleared home. A Sylvania garden full of established shrubs, where Argentine ants climb the trunks to reach aphids and then march through the back door on wet days, calls for ant treatment in Sylvania that covers the yard and the building edges, because the technical note says an entire block may need treatment for this species.
Do ant baits actually work?
Baits can work, but they are slow and species specific. The technical note says workers carry bait back and share it through the nest, which can eliminate the whole colony. It also says baiting needs patience, the formulation must attract the species being controlled, and children and pets must be kept safe.
That is where supermarket baits usually fall down:
- A sweet bait laid for coastal brown ants, which prefer grease and protein, may simply be ignored.
- Bait set near a fruit bowl or an open bin competes with better food.
- Spraying near bait kills the very workers meant to carry it home.
A Woolooware family with toddlers and a dog, finding ants around the kitchen bin and wary of loose bait stations, is better served by quick ant control in Woolooware, where a technician identifies the species first and chooses treatment with children and pets in mind.
Are flying ants a sign of termites?
Not always. The technical note states that ants are not related to termites and cannot damage sound timber. Ants have elbowed antennae and a pinched waist, and winged ants have forewings larger than their hind wings. Carpenter ants, sometimes called sugar ants, prefer moist, rotting wood and rarely cause structural damage.
If you find discarded wings on a windowsill or insects leaving damp timber, have them identified, because termite treatment is completely different from ant control.
When should you book ant control?
Book a technician when any of these apply:
- Trails return within a couple of weeks of spraying or cleaning.
- Ants are nesting inside ceilings, wall cavities or subfloors.
- Ants appear in power points, switchboards or appliances. The technical note says Singapore ants are attracted to plastics in electrical equipment, frequently nest in power sockets, chew wiring and have been responsible for electrical fires.
- A nest sits in a lawn, garden bed or play area where stings are a risk.
healthdirect's insect bites and stings guide warns that repeat exposure to ant stings may increase sensitivity to the venom, and advises always having ant, bee and wasp nests removed by professionals. The Australian Museum's bull ant page records nine bull ant species in Sydney that attack intruders near the nest. A Greenhills Beach backyard where a bull ant nest has opened beside the children's trampoline needs ant control in Greenhills Beach before the next barefoot afternoon outside.
Before you book
Note which rooms the trails run through, what food they go to (sweet or greasy), whether ants have appeared in power points or appliances, where outdoor nests sit, and what sprays or baits you have already used. Send those details when you contact our pest control service in the Sutherland Shire, and you will get clear steps for ant control aimed at the colony and every nest feeding it.