WA’s Peskiest Critter: Coastal Brown Ants

avoid an ant infestation

Summer backyard barbeques are part of life in Australia, whether you team them with some backyard cricket or footy, swimming in the pool or just enjoy time sitting around with family and friends. However, all too often, some nosey ants, who want some of your snags, a bite of your roll, or to use your cordial as their personal swimming pool, interrupt these moments. These insects, particularly the coastal brown ant, are a major nuisance in Western Australia; they are a notorious urban pest, and difficult to get rid of.

Thankfully, that is where we come in. As West Australians ourselves, The Pest Guys understand the local pests and the best ways to get rid of your ant infestation.

DefiANT Pests

The coastal brown ant – also referred to as the “big-headed ant” – is believed to be native to Africa, but can now be commonly found in our lawn and brick paving. These ants are small, light brown or ginger in colouring and have shiny dark brown abdomens.

There are two types of these ants:

  • Smaller “minor” ants – 2-3mm long
  • Larger “major” ants – 3.5-4mm long

Major ants make up only 1% of the coastal brown ant population, but they have an important job in their colonies. The major ants have a distinct large head with a powerful jaw, which they use to break down pieces of food so that the smaller worker ants can transport it more easily back to the colony.

Signs of an Ant Infestation

Any pest infestation should be acted on quickly, as there may often be damage that you can’t see! Some of the signs of a coastal brown ant infestation are:

  • Small mounds of excavated soil on your lawn, in between your paving or in the soil of your garden bed. This excavated soil is the result of the inter-connected tunnels that the ants have developed underground.
  • Brick paving may become destabilised, as the sand/soil from underneath has been moved by the ants
  • Plants dry out and die; this can be due to the roots of your plants and lawn becoming so aerated by the ants that they aren’t able to get nutrients from the soil they are in.

While the damage done by these pests may not be visible or seem severe at first, the repair bill, if left untreated, can really add up!

Negative Impact of Infestation

The signs of an infestation may not look like much, but removing the ants and repairing the damage done to things such as plants, lawn, paving and brickwork, can cost time and money.

These ants can also do damage to external electrical appliances, such as hot water systems! Other than the cost that comes with the repair of electric systems, the damage can also result in the electrics short-circuiting, which is a fire hazard.

From a hygiene point of view, these pests can also carry bacteria such as salmonella. A salmonella infection may include symptoms such as fever, diarrhoea, loss of appetite, headache, stomach cramps, nausea and vomiting.


These ants can be spread unintentionally, particularly if someone is moving house and taking plants with them, or moving food or rubbish. Therefore, it is important to check things such as pot plants for ants before you move them.

There is not much that can be done to prevent the ants making a home in your garden, but you can prevent an infestation from doing severe damage if you catch the signs early. If you do spot tell-tale signs of an ant infestation, don’t hesitate to contact The Pest Guys. Where there is sign of one nest, there may be many more lurking beneath the surface.

The Pest Guys employ non-toxic treatment methods to ensure you and your family remain safe both during and after the treatment. Our professional team are ready to help, so contact The Pest Guys today to find out how we can help you and your family with your pest control needs.