Coastal Brown Ant

The coastal brown or big-headed ant is a pest of houses, gardens and natural environments in the Northern Territory. It is thought to be a native of southern Africa but has spread over much of the tropical and sub-tropical world. The ant is spread mainly by human activity, such as the transfer of infested pot plants and landscaping materials to un-infested houses and gardens. The coastal brown ant also poses an ecological threat to Top End rainforests by destroying native fauna and flora.


The coastal brown or big-headed ant is a small ant 1.5 to 2.5 mm long. The colour of the ant varies from light yellowish brown to dark brown. Coastal brown ants travel in trails from the nest to food. The ant has four castes or body forms. The largest form is the queen, which lays eggs. Unfertilised eggs produce males and fertilised eggs produce females. There are many queens in coastal brown ant nests. Males are the next largest form and are elongated in shape. By far the most numerous forms are the workers. The large headed form defends the colony and is sometimes known as the soldier caste. One of the ant’s common names is taken from this form. Queens and males are rarely seen outside the nest


The ant is thought to have originated in southern Africa and has now spread all over the Old-World tropics and into many temperate areas. In Australia, the ant has long been established along the east coast and the south-western corner of WA, around Perth. It is commonly found in the urban areas of Alice Springs, Katherine and Darwin, where it is a domestic nuisance feeding on food scraps and invading kitchens and bathrooms in search of food.


In the Top End, the coastal brown ant avoids bright sunlight and prefers lower temperatures and high humidity. As a result, the ant is more numerous in moist shaded areas. When temperatures are high workers forage only at night. Covered galleries or runways made of soil and organic matter are constructed on the trunks of shrubs and trees. This allows workers to travel up and down the trunk without being exposed to the high temperatures and lower humidity levels outside the runways. Heavy rainfall and waterlogged soils are unfavourable to the coastal brown ant. Ant activity and populations are lowest during the wet season. To avoid waterlogged soil the ant will invade houses and make subsidiary nests in trees and shrubs. Since the coastal brown ant does not have a mating flight, it is spread mainly by human activity. In suburban areas, the transfer of infested pot plants and landscaping materials to un-infested houses and gardens appears to be the main method by which the ant is spread over longer distances.

Book your pest control service today!


Nests are constructed in gardens, (particularly when landscaping materials and mulch are placed over garden soil), in pot plants and in crevices between brickwork, in cavity walls, under pavers, under concrete paths and under poorly constructed concrete slabs.


The ant prefers food of animal origin such as meat particles, urine, fat and grease, and dead insects. A fine layer of grease over kitchen walls, stoves, dish cloths and kitchen utensils is attractive to the workers. Soiled clothing may also attract the ant.


The coastal brown ant enters houses in search of food. Kitchens and bathrooms are the most attractive to the ant, although other parts of houses are also invaded. Ant trails inside the house usually lead to cracks and crevices between brickwork and tiles, around skirting boards and gaps in wooden floors. Once inside houses the ant can nest in light switches, computers and household appliances. In the garden, the ant will excavate nests in soil at the base of trees and shrubs. The excavation disturbs the root system of the plant, sometimes resulting in the death of the tree or shrub.

Contact us now at 1800 819 189 to schedule a free consultation and learn how we can help you with Ant pest solutions that work or fill out the form below to get started.

    Read the terms and condition here.

    Why Choose us?

    100% pest control guarantee

    We guarantee to rid your home or business from pests and offer all customers a 3-6 month warranty.

    Free Quotes & Advice

    Call, Email or Instant Message us and we'll give you honest advice on how to effectively solve your pest problems.

    100% Customer Satisfaction

    We're not happy unless you are! We promise to return for free if pests reappear during your warranty period.

    Residential & Commercial

    We specialise in the removal and prevention of pests for all types of properties and sizes.

    100% Money Back Guarantee

    If you're not totally satisfied with the results of our work then we promise to provide you with a full refund.

    Same Day Express Call Outs

    Get in touch and one of our qualified pest technicians can meet and treat on the very same day!

    Why our clients love us

    • They got rid of cockroaches at my place - 0 cockroach sighting 2 months later!! (they were coming in from surrounding apts). The technicians are very experienced at their... read more

      Cecilia Avatar Cecilia

      Blake is very professional. His work has been very thorough and very efficient. Since we use their service we have never have any issues with pest control at... read more

      Joy Kawser Avatar Joy Kawser

      I went with the general pest control service. John was amazing. He arrived early. He explained the treatment thoroughly before he started. After the treatment, he explained what would happen... read more

      Phuc Avatar Phuc
    • Very prompt communication from the customer service team, considerate when I had to change date and made rebooking easy. The service was good as well, thorough and reasonably priced. Will... read more

      Leanne Chen Avatar Leanne Chen

      We have had 2 treatments at 2 different properties with Sydneys Best Pest Control and the service and treatments provided have been no less than fantastic. The technicians were on-time... read more

      Stephanie Knight Avatar Stephanie Knight

      Very impressed with Pest Control Sydney. As arranged, Alex arrived at 7am on the dot (maybe even a few minutes early). Not only was he super friendly, engaging and... read more

      Pat Khoo Avatar Pat Khoo
    • 100% best pest control company out there. So friendly, extremely efficient at getting back to you, great advice and knowledge on all kinds of pests. Used them at my apartment... read more

      katie teo Avatar katie teo

      I spoke to Pierre on the phone to get a quote and recommendation on flea treatment. The recommendation given to me was genuine and really in the best interest of... read more

      Morena Koh Avatar Morena Koh

      Excellent, very professional company. Very organised and disciplined They have a dedicated pre-service chat/email team that looks into what bugs you have. And puts together a detailed... read more

      Paul L Avatar Paul L
    • Definitely the best pest control service. We've had them work on our house twice and they've been able to resolve our pest issues. The workers were friendly, helpful and were... read more

      U Green Avatar U Green

      We have had 2 treatments at 2 different properties with Sydneys Best Pest Control and the service and treatments provided have been no less than fantastic.
      The technicians were on-time and... read more

      Stephanie Knight Avatar Stephanie Knight

      Provided good advice and were very helpful along the way.

      Andre Emery Avatar Andre Emery