Invasive Ants

Introduced ants are some of the greatest environmental and economic threats to northern Australia. They can form super colonies that can eliminate many native animal species, seriously disrupt ecological processes, and sting - preventing people from enjoying the outdoors. Ants are easily transported by people for example in pot-plants, landscaping material and earth-moving machinery.

The most serious invasive ant species occurring on the Tiwi Islands are African big-headed ants (Pheidole megacephala) and Singapore ants (Trichomyrmex destructor).

African Big-headed Ants

African big-headed ants (Pheidole megacephala) are small (about 2 mm) and vary in colour from light to dark brown. The major workers (approximately 1 in 100) have very large heads. African big-headed ants are slow moving, do not bite or sting, and have no smell when crushed.

They nest in a wide range of places including lawns, bases of trees, within cracks or crevices in paving or concrete, hollowed logs, up trees, and in pot plants. Nests are easily noticed as the soil is mounded up and the many entrances are obvious.

African big-headed ants are a major threat to biodiversity, particularly in rainforests, as they out-compete and displace native invertebrates. They are also a serious pest in buildings, forming large colonies where food scraps or refuse is available, and can cause damage to electrical items.

Singapore Ants

Singapore ants (Trichomyrmex destructor) are pale yellow to brown in colour. Individuals are small (1.8-3.5 mm) and very slow. Workers can vary in size and have a painful sting. They are highly destructive - they are known for chewing through electrical wiring, insulation, and plastic in homes and vehicles.

Singapore ants commonly form large colonies within and around buildings. Most nests are located inside buildings, under paving or in the ground between plants. However, they can also inhabit areas far from infrastructure where they outcompete native fauna.