Bull ants and stings
Bull ants give painful stings, and healthdirect says they sometimes cause anaphylaxis (a severe allergic reaction). If that happens, use an adrenaline autoinjector straight away, then call 000. Keep children away from a bull ant nest until it's dealt with.
Ants around Perth homes
Argentine ants come back fast
DPIRD, WA's agriculture department, says the Argentine ant is the most difficult common pest ant to control, because it re-colonises treated areas quickly. Victoria's Health department puts it at within two weeks, from neighbouring land.
Holes and little mounds in the lawn or pavers
DPIRD says coastal brown ant nests show up as lines of interconnected holes and small soil mounds in lawns and brick paving. That's often the first thing a Perth household notices.
Singapore ants and wiring
DPIRD lists the Singapore ant as established in WA. Victoria's Health department says it can nest in power sockets and chew wiring, and has been behind electrical fires, so ants around a power point are a job for someone with the right tools.
Exotic ants are reported
If an ant looks unusual, DPIRD asks you to report it with the MyPestGuide Reporter app rather than treat it. A photo from close up helps.
Which Perth ant is it?
| Argentine ant | Coastal brown ant | Black house ant | |
|---|---|---|---|
| Size | 1.5 to 3 mm | Workers 1.5 to 3 mm; soldiers 3.5 to 4.5 mm | 2.5 to 3 mm |
| Colour | Slender and brown, with no smell when crushed | Shiny light to dark brown; soldiers have big heads | Intensely black, with a strong smell when crushed |
| What you notice | Slow, well-defined trails three or more ants wide, often up tree trunks | Lines of holes and small soil mounds in lawn and paving | Nests along paths, and indoors in ceilings, cavity walls and subfloors |
What a Perth ant treatment involves
The technician should start by working out which ant you have and where it's nesting, because the treatment follows from that. Baits placed along trails are meant to be carried back to the nest; a treatment around the outside of the house is aimed at ants coming in from the yard. Which suits depends on the species.
Spraying the trail you can see isn't always the answer. Victoria's Health department says spraying Pharaoh's ants splits the colony into new ones and tends to make things worse. Ask the technician why they're choosing the method they recommend.
What makes the job bigger: ants nesting inside walls or ceilings, Argentine ants spread across the whole block or from next door, and a follow-up visit when the first round only pushes them back.
What you can do, and what to hand over
You can
- Keep sweet food, pet food and the bin sealed, and wipe up spills straight away.
- Trim plants and branches that touch the house; they're ant bridges.
- Fix leaking taps and dripping hot water overflows near the walls.
- Note where the trail goes in and take a close photo of one ant for identification.
Leave to a pest business
- Ants nesting in walls, ceilings or under floors.
- Argentine ants across the yard, where treated ground gets re-colonised from outside.
- Ants around power points or switchboards.
- A bull ant nest near a path or play area.
Where we'd start with ant control in Perth
We'd get a clear photo of one ant and note where the trail goes before anyone sprays anything. If it's inside the walls, around wiring or back within a fortnight, tap Spiders or ants with what you've seen.
Want someone to look at it?
Tell us what you've seen and your postcode, and a local pest business that handles exactly that calls you to talk it through.
