⚡ TL;DR: Quick Summary
- The colony is the real target: the ants on your bench are only a small share of the nest, and the queen keeps replacing every worker you kill.
- Many Perth pest ants have several queens: Argentine and coastal brown ants can run huge multi-queen colonies, so one surviving queen restarts the problem.
- Sprays often make it worse: they kill the ants you can see, scatter the rest, and can split a colony into new nests.
- Baits work because ants share food: place slow-acting bait on the trail, leave it alone, and allow at least two weeks for a colony to collapse.
- Flying ants mean a mature colony nearby, and anything with straight antennae and no waist should be checked for termites.
- Professional help: Rockypest ant treatments start from $250 and include a 3-month warranty.
There are about a quadrillion ants trying to invade our homes when they feel like it, especially during extreme weather. They are in the corners, crevices, on the kitchen counter, or inside food containers.
Some are small. Others are big. Some are black, while others are red.
And, whether their bite stings or not, their number can be troublesome. Why are ants so hard to get rid of?
Reasons Why Ants Are Hard to Get Rid Of
The short answer: you are not fighting the ants you can see, you are fighting a hidden colony that is organised, resilient and very good at replacing its losses. Here is what makes them so stubborn.
1. Ants Have Amazing Teamwork
In a colony of ants, there are roles played. Such functions are focused on preserving the life of the queen ant and her eggs.
- Worker ants, or the smaller ones, protect the queen and her larvae.
- Storage ants keep food in their bodies and regurgitate them when other ants go hungry.
- There are ‘poison testers’ that dilute and mix food before passing it on to the queen for consumption. In most ant species, the queen is the only individual who can produce new workers. So, to destroy the colony, you need to kill the queen.
What this means in your kitchen: the ants marching across the bench are foragers, only a small portion of the whole colony. Squash or spray them and the queen, safely tucked away in the nest, simply lays more eggs to replace them.
2. They Have Incredible Discipline (and Pheromones)
Notice how ants always follow a single line. It’s because of the pheromones they leave on their track on the way to the food.
The ant that finds the food drops pheromones on its way, and the other ants instinctively smell it and follow to help transport it to their nest.
Why the trail keeps coming back: wiping ants off the bench does not remove the scent they laid down. Unless the trail is cleaned properly, the next wave of foragers can pick up where the last one left off, which is why the same line often reappears the next day.
3. Many Colonies Have More Than One Queen
Some ant species rely on a single queen, but several of Perth’s most troublesome pest ants do not. Argentine ants and coastal brown ants can run large colonies with many queens spread across multiple connected nests.
That changes the maths completely. Knocking out one nest or one queen barely slows the colony down, because the others keep producing workers and can even raise replacement queens.
4. Sprays Kill the Wrong Ants
Surface sprays only kill the ants they touch, and those are mostly foragers. The queens, eggs and larvae deep inside the nest are untouched.
Many household sprays are also repellent, so ants simply detour around the treated area and find another way in. The result feels like the spray worked for a few days, followed by ants turning up somewhere new. This is exactly the short-lived effect that has so many Perth homeowners buying can after can.
5. Some Species Split When Disturbed
When certain multi-queen species are stressed, for example by a spray, they respond by budding: groups of workers carry brood and one or more queens off to start a brand-new nest nearby.
Pharaoh ants and Argentine ants are well known for this. So a colony that was living in one wall cavity can end up in three or four, making the problem bigger rather than smaller.
6. Their Nests Are Hidden Out of Reach
Ant nests are rarely where you can see them. They sit in wall cavities, under concrete slabs and paving, beneath garden edging, in pot plants, and in the sandy soil so common across Perth and the Peel region.
You can pour boiling water or powder onto an entrance hole, but the main chambers are often well below the surface or spread under the house, far from anything a DIY product can reach.
7. Perth’s Weather Drives Them Indoors
Our hot, dry summers send ants searching for water, and kitchens, bathrooms and pet bowls are the easiest sources around. Heavy winter rain does the opposite, flooding nests and pushing colonies up and inside to stay dry.
That is why ant activity often spikes after a heatwave or a big downpour, which matches the extreme-weather invasions described above.
Related → Why Have Ants Suddenly Appeared in My House? | Pavement Ant Control | How to Keep Your Perth Home Ant-Free in Winter
The Perth Ants That Are Hardest to Shift
Knowing which ant you have is the first step, because each species nests, feeds and responds to treatment differently. These are the ones Rockypest technicians see most often causing repeat problems.
Argentine ant
Look: Dark brown, 2.2 to 2.8mm
Why it’s tough: Multi-queen colonies that bud when disturbed, with long trails running indoors from foundations and damp garden areas.
Coastal brown ant
Look: Yellow to brown, 1.5 to 2.5mm
Why it’s tough: Multi-queen nests in lawns, garden beds and under pavers, drawn to oily foods, fruit and sweets. Often pushes sand up between paving.
Black house ant
Look: Shiny black, 2.5 to 3mm
Why it’s tough: Common in kitchens and along pathways, strongly attracted to sweet foods. Trails reappear quickly if only sprayed.
Carpenter ant
Look: Larger, black or brown and orange
Why it’s tough: Nests in damp or decaying timber, wall cavities and tree stumps. A sign of moisture problems worth investigating.
Related → Common Australian Ant Pest Types | The Danger of Carpenter Ants
Common DIY Mistakes That Keep Ants Coming Back
Most ant problems that drag on for months are not caused by a lack of effort. They are caused by treatments that work against how the colony behaves.
🧴 Spraying the trail: It kills the visible foragers, scatters the rest and can trigger budding into new nests.
🍯 Spraying near baits: Surface spray contaminates bait so ants avoid it, undoing the one method that reaches the queen.
🧽 Wiping ants but not the scent: Removing ants without cleaning the pheromone trail leaves a road map for the next wave.
⏱️ Giving up on bait too early: Baits are slow on purpose. Removing them after a day or two stops the colony being fed the active ingredient.
🏠 Treating inside only: The nest is often outside, under paving or in garden beds, so indoor-only treatment leaves the source untouched.
Warning: store-bought ant baits, gels and powders must be kept well out of reach of children and pets, and used exactly as the label directs. Place baits behind appliances, inside cupboards or in enclosed stations rather than on open floors where little hands and paws can find them.
Related → Ant Control: DIY vs Professional Treatments | 6 Ways to Get Rid of Ants Naturally
How to Bait Ants the Right Way
Baits turn the colony’s teamwork against it. Foragers carry the slow-acting bait home and share it mouth to mouth with other workers, larvae and the queen, so the treatment reaches parts of the nest no spray ever could.
Phase 1: Set the bait
Find the trail. Follow the ants back as far as you can and note where they enter the house, such as a skirting gap, window frame or slab crack.
Match the bait. Place bait right on the trail. If ants ignore it, try a different type, since some species prefer sweet baits and others prefer protein or oily ones.
Leave it alone. Do not spray, wipe or disturb the trail while ants are feeding. Top the bait up if they empty it.
Phase 2: Close the door behind them
Clean the trail. Once activity has stopped, wash the old trail with warm soapy water to remove the lingering pheromones.
Seal the entry. Fill the cracks and gaps they were using and fix any leaks or damp spots that drew them in.
Remove the rewards. Keep food sealed, benches crumb-free and pet bowls clean so new scouts find nothing worth reporting.
Important: once bait is down, resist the urge to spray. More ants at the bait for the first day or two is a good sign that they are carrying it home.
🔎 What Your Bait Results Are Telling You
✅ Busy bait for a few days, then activity steadily drops
The bait is being shared through the colony. Keep it in place until the trail has stopped completely.
➖ Ants walk past the bait without feeding
The bait type does not suit this species or its current diet. Try a different formulation on the same trail.
⚠️ Still heavy activity after two weeks, or new trails in other rooms
You are likely dealing with a multi-queen colony, several nests or budding. This is the point to call in a professional.
Clearing a whole colony usually takes at least two weeks, and larger colonies can take longer.
Related → List of Effective Ant Control Tips | How to Permanently Get Rid of Ants
Flying Ants: What They Tell You
Winged ants are the colony’s future kings and queens, leaving the nest on warm, humid days to mate and start new colonies. Seeing them does not mean ants have learned to fly, but it does mean there is a mature, well-established colony close by.
Seeing them indoors is the bigger concern, because it suggests the nest may be inside a wall cavity, roof void or under the floor rather than out in the garden.
Warning: flying termites are often mistaken for flying ants, and termites are a far more serious threat to a Perth home. Ants have a pinched waist, elbowed antennae and front wings longer than the back ones. Termites have a straight, thick waist, straight beaded antennae and four wings of equal length. If in doubt, collect a few in a sealed jar and book an inspection.
Related → Termites: White Ants | Timber Pest Inspection
When to Call a Professional
📞 Signs It’s Time to Call an Ant Specialist
- You have sprayed repeatedly and the ants keep returning.
- Trails are appearing in several rooms at once.
- Ants seem to be coming from inside walls, ceilings or under the floor.
- Baiting has not made a dent after two weeks.
- You are seeing flying ants indoors, or you are not sure if they are termites.
- Large ants are active around damp or damaged timber.
A licensed technician identifies the species, tracks down where the colony is actually nesting, and chooses the right mix of treatments for that species rather than a one-size-fits-all spray.
Related → The Benefits of Professional Ant Pest Control | How to Choose a Professional Ant Control Service
Contact Rockypest Today
Given that they are both smart and adaptable, getting rid of ants is an absolute struggle. Instead of repeatedly wasting money on pest spray with a short-lived effect, call a professional pest control service.
To get help in controlling ants in Perth, reach out to us at Rockypest today. We have pest control packages that cater to various needs.
💲 What Ant Control Costs with Rockypest
Prices as listed on Rockypest’s current price list. Treatment depends on the ant species and may involve spraying, dusting, baiting or a combination. Inside and outside treatments require you to be out of the house for at least three hours afterwards.
Tired of Ants Coming Back?
Rockypest’s licensed technicians identify the species, find the colony and treat it at the source, with every ant treatment backed by a 3-month warranty.
Servicing Rockingham, Baldivis, Mandurah, Kwinana, Fremantle, Armadale, Secret Harbour, Port Kennedy, Canning Vale, Greater Perth.
Ant Control FAQs
Why are ants so hard to kill?
Because the ants you see are only foragers. The colony, its eggs and its queens stay hidden in the nest, and many pest species have multiple queens and several nests, so killing visible ants barely affects the colony.
Why do ants come back after spraying?
Sprays only kill the ants they touch and often repel the rest, which then find another route inside. Some species also split into new nests when sprayed, so the problem can spread.
See → DIY vs Professional Ant Treatments
How long does ant bait take to work?
You should see activity rise at the bait for a day or two, then fall as it is shared through the colony. Fully clearing a colony takes at least two weeks and, for large colonies, sometimes months.
See → Ant Control Perth
Do you have to kill the queen to get rid of ants?
Yes. The queen is the colony’s only source of new workers in most species. In multi-queen species such as Argentine and coastal brown ants, every queen needs to be reached, which is why slow-acting baits work better than sprays.
Why have ants suddenly appeared in my house?
Usually because scouts have found food or water, or because hot or wet weather has pushed a nearby colony indoors. A single trail can build quickly once the pheromone path is laid.
See → Why Ants Suddenly Appear
Are carpenter ants as bad as termites?
Generally not. Carpenter ants hollow out damp or decaying timber to nest but do not eat wood the way termites do. Their presence can still point to moisture damage, so it is worth having the timber checked.
See → The Danger of Carpenter Ants
How can I tell flying ants from termites?
Ants have a pinched waist, elbowed antennae and uneven wings. Termites have a thick straight waist, straight antennae and four equal-length wings. If you are unsure, book an inspection.
See → Termites: White Ants
Are tiny black ants harmful?
They are mostly a nuisance rather than a danger, but large numbers in the kitchen can contaminate food and are frustrating to shift without targeted baiting.
See → Common Australian Ant Pests
How much does ant control cost in Perth?
Rockypest ant treatments start at $250 for outside only on a single-storey home, up to $330 for inside and outside on a two-storey home, all with a 3-month warranty.
See → Current Price List
Do I need to leave the house during ant treatment?
For inside and outside treatments, yes, you will need to be out of the house for at least three hours afterwards. Outside-only treatments do not require this.
See → Preparing Your Property for Ant Control
What should I do after an ant treatment?
Avoid cleaning treated areas or disturbing baits straight away, keep food sealed, and expect some ant activity for a short time as the treatment works through the colony.
See → What to Do After Ant Pest Control
References
Rockypest Pty Ltd, servicing Rockingham, Baldivis, Mandurah, Kwinana, Fremantle, Armadale, Secret Harbour, Port Kennedy, Canning Vale and greater Perth, WA, with pest control experience since 1988.
