Tips to Control an Ant Infestation

Last Updated: July 16, 2025
Gordon Reidy
Ant Control, General Pest Control

Most homeowners struggle to get rid of ants……. and it’s not easy, even for professional pest controllers! To get lasting control of ants you need to kill the whole nest, particularly targeting the queen(s). To do this successfully you need to be able to identify the species, understand their colony structure and foraging behaviour, and then know which products to use and how to use them. So here’s a crash course to help you on your way…

With thousands of ant species present in Australia, identifying a particular species is normally a job for experts. Here are the most common problem ants found around homes and how to identify them.

Indoor ants

Black House ant

Black house ant
The black house ant is a small, shiny black ant

Nest location: Nest inside and outside. Particularly like wall voids and roof cavities under insulation.

Behaviour: Can develop long trails.

Food preference: Sugar.

Recommended control products: Sugar based ant bait for nest treatment if nest cannot be located, powder treatment if nest can be located.

White footed house ant

White footed ant
The white footed ant has a large abdomen and pale ends to its legs

Nest location: Nest inside and outside. Particularly like kitchens and bathrooms.

Behaviour: Can develop long multi-lane trails on exterior walls.

Food preference: Sugar.

Recommended control products: This species often has multiple nests and multiple queens and is very difficult to control. Try and locate all nests and treat with sugar based baits or directly with insecticide powder. Spray outside walls where the ants are trailing.


Argentine ant

Argentine ant
Argentine ant is a small brown ant

Nest location: Nests around the perimeter of the house in garden beds and under sheeting – very shallow nests.

Behaviour: Can dominate whole areas, creating a super colony that can grow to many kilometres! These ants live outside but sometime come inside looking for food.

Food preference: Sugar in cooler months, protein in Spring / Summer.

Recommended control products: Due to the massive size of the colonies, spraying the nests directly provides the best results. But this needs to be repeated regularly to keep the numbers down.


Outdoor Ants

Coastal brown an (big-headed ant)

Coastal brown ant
The coastal brown ant is a small red / brown ant, some workers with big heads

Nest location: Outside in lawns and under pavers.

Behaviour: Can form multiple nest colonies, does a lot of excavating.

Food preference: Protein / Oil

Recommended control products: Nests can be treated with granular baits. Excavation areas can be treated with an insecticide spray or granule / sand.

Tyrant ant

Tyrant ant
The tyrant ant is a fast moving, outdoor ant

Nest location: Outside in lawns and paved areas.

Behaviour: Fast moving. Aggressive with mild sting.

Food preference: Sugar and protein.

Recommended control products: Nest can be treated with granular ant baits. In areas where they may be causing a problem with pavers use an insecticide spray or granule / sand.

Green-head ant

Green-head ant
The green-head ant is a black ant with green / blue iridescent sheen

Behaviour: Aggressive with painful sting.

Nest location: Outside in lawns and garden beds.

Food preference: Protein

Recommended control products: Treat nests with granular ant baits.


To get rid of ant infestations and provide lasting protection, typically a combination of products needs to be used. Often, due to the number of nests / large ant numbers, repeat applications may be necessary.

You don’t just want to kill ants, you need to kill the nest…

To get lasting control, you need to kill the nest. There are three potential products that can be used for nest control; baits, sprays and powders

Ant baits are the smart way to achieve nest control. Ant baits consist of a food attractive to the ants and a slow acting insecticide. The ants take the bait back to the nest where it is fed to their nest mates including the queen. The food is passed around the nest before the insecticide starts to have its effect and the colony is doomed.

There are two key challenges when using ant baits. Firstly, the bait needs to be attractive to the ants – with different ant species having different food preferences and often changing their preferences through the year, choosing the right ant bait can be a challenge. Secondly, it is important to make sure you apply enough ant bait to control the colony – the bigger the nest, the more bait that is required.

Generally speaking, ants can be split into sugar feeders, protein feeders and oil / fat feeders. Whilst it is not always the case, often the black ants (especially those found in houses) tend to have a sugar preference and the brown ants (especially those found outside) tend to have a protein / oil preference.

PestXpert nest kill ant bait
PestXpert Nest Kill Ant Bait

Sugar based ant baits for homeowners either come as a liquid (eg.Ant Rid) or as a solid bait in a bait station (eg. Mortein ant baits). These baits should be placed near the ant foraging trails and replenished as long as the ants continue to forage. (Place the liquids in a dish or sheet of aluminium foil). Ant numbers should drop off in 2-3 days and nest control should be achieved in around a week. However, although they may deliver a temporary drop in ant numbers, some of the liquid products are not always effective at delivering nest kill. Unfortunately some of the best sugar based ant baits (ant gels) are only available to professional pest controllers, but this may change in the future.

For outdoor ant species, use of a granular ant bait applied to trails or nests, or indeed over the infested area, can deliver great colony control. Again, it is a question of choosing a bait that is attractive to the species present. Fortunately, PestXpert Nest Kill ant bait contains two different types of food granules to appeal to a wider range of species. Treatment should deliver a drop in ant numbers in 2-3 days with colony control in 1-2 weeks. Large nests may require a supplementary treatment.

PestXpert Outdoor Perimeter
PestXpert Outdoor Perimeter

To treat an ant nest directly, the first challenge is to try and find the nest. Do this by following the ant trails. If you can see the ants carrying food, they will be going back to the nest, so those will be the ones to follow. Outdoor nests can be treated with a liquid insecticide.

To treat the nest with an insecticide spray, you need a product with a sturdy spray wand that allows you to inject the insecticide into the nest – PestXpert Outdoor Perimeter with its 1m spray wand is ideal. However, as it is not possible to know the internal nest structure, when you “inject” insecticide into the nest, you need to try and “flood” the nest so maximise the chances of success.

Powders can be useful if the nest is located inside – in the roof or wall void. Blow powder into the nest, ideally from a couple of different angles. Certainly in areas where electrical issues may be a concern, powders are the product of choice.

To keep ants out of the house

Spraying around the perimeter of the house (1m up the wall and 1m out) and around doors, windows and other entry points can help keep ants out. Some of these treatments may have a short term repellent effect, but their main mode of action is to kill ants that walk across the treated surface. If there are large numbers of ants or the treated surface is exposed to sun and rain, then the treatment may not last long. This is why sprays should be used in conjunction with baits to kill the nest.

To keep ants out of pavers

Ants build their nests under the pavers of paths and driveways…. the piles of sand and dirt are their excavations. Applying a long lasting insecticide to the cracks and crevices will kill any ants present and prevent the ants returning for several months. A professional liquid spray such as PestXpert Pro-Spray Outdoor is ideal for this job. Although this treatment will kill ants on contact, it does not normally kill the nest and often the ants may move elsewhere. The treatment acts more like a repellent, keeping the ants out of the paved area. The repellent effect wears off over time and so re-treatment will be necessary every 2-3 months to keep the area clear of ants.

To keep ants out of the lawn

Granular baits (such as PestXpert Nest Kill ant bait) should be the first course of action, especially for species such as the green-head ant, as it actually kills the nest. However, the use of ant granules or ant sand sprinkled over the infested lawn can also have an impact in reducing ant numbers as they contact the treatment. However, excluding all ants completely from a lawn is impossible, as sooner or later they will move in from neighbouring areas.

IMPORTANT NOTE: Granular ANT BAITS are not the same as insecticide granules (or sand). Baits contain food and are taken back to the nest – they are designed to kill the whole colony / nest. Insecticide granules are a contact insecticide, killing insects when they come into contact with the granules – they are designed to exclude insects from a particular area, they are unlikely to kill the nest.

It’s an ongoing battle…

Whilst dealing with a nest inside the home is typically a one-off event and you normally get long lasting results, dealing with ants outside the home can be an ongoing battle. Even if you get good levels of control, it is only a matter of time before new ants can move in from next door (something you can blame the neighbours for!). As such lasting ant control often requires regular treatments throughout the year…. and a lot of persistence!

More details on how to get rid of ants…PestXpert have a range of ant control products

Originally Published: November 13, 2016
author bio image

Author:

Gordon Reidy has over 30 years experience in Pest Control Product Development and Product Safety. As the lead formulator at PestXpert, he has helped develop some of Australia’s most trusted household pest solutions. With a PhD in Toxicology, Gordon is passionate about delivering effective, science-backed products that are safe for families and the environment.

Share This Post

Further Reading

  • Slater or woodlouse
    How to Stop Slaters Invading Your Home

    Slaters entering the home can be a problem in Australia. Learn how to keep slaters out of your home and how to control them.

  • Indian meal moth or pantry moth
    What's Eating My Food? Pantry Insects

    Pantry pests is a common name given to insects that infest stored products such as flour, cereals and indeed any dried foods. Sometimes you may not be even aware your food has been infested, but when you do… yuck! But…

  • Coastal brown ants taking bait granule back to nest
    How do Ant Baits work?

    It is important for those carrying out DIY pest control to know how ant baits work, so they can choose the correct ant bait for their particular situation. Ant baits – Basic Information What goes into an ant bait? Ant…

  • big headed ant or coastal brown ant
    Types of Brown Ants in the House and Yard

    It’s a weird thing… generally speaking, in Australia, brown ants seem to be more of a pest outside the home than inside the home, whereas black ants tend to be more of a pest inside the home. Let’s have a…

  • Tyrant ant
    Types of Black Ants in the House and Yard

    Finding black ants in the house is a pretty common problem. However, getting rid of the ants isn’t always that straight forward. To get control you need to be able to identify the ant species and know a bit about…

  • Carpet beetle larva
    5 Facts About Carpet Beetles You Need to Know

    Carpet beetles are a common fabric pest. Although their name indicates they only eat carpets or rugs, they will eat a wide range of animal fabrics including wool, fur, silk, felt, feathers and leather. As with any pest problem it…

  • Silverfish
    10 Places Silverfish Like to Hide in your Home

    Secretive and nocturnal, a silverfish infestation can go unnoticed for some time. A versatile, primitive insect, silverfish can inhabit a wide range of hiding places in your house. Silverfish like to eat starchy foods, so they find paper and cardboard…

  • cockroach on pear
    Spring Cleaning? Do a Pest Spray!

    With the temperature warming up, everyone thinks about clearing up the yard for outdoor entertaining, which often leads to cleaning out the garage and then the house – a good Spring clean! If you are giving your house and yard…

  • Dog with petfood bowls
    Safe pesticide use for pet owners

    “Are insecticides safe to use around my pets?” is perhaps one of the most common question homeowners ask about pest control products. It’s a good question…. and important, because when using any pest control product, safety comes first! Learn more about…

  • Spraying house
    DIY Pest Control - Which insecticide should you choose?

    Everything you need to know about white tail spiders: What do they look like? Where do they live? Information on white tail spider bites - is the flesh eating spider bite a myth? How to get rid of white tail…