Of the estimated 4-5,000 species present in Australia very few are troublesome, and these are mostly “vagrant” or “tramp” species which have been accidentally introduced from overseas. The tramp species (the Singapore Ant, the Coastal Brown Ant, the Argentine Ant, the White-footed House Ant, Pharaoh’s Ant, and the Black House Ant) infest buildings in search of water and food, and will take all kinds of domestic foods, ranging from oils and butter to sweet substances, meats and grain-based items like bread and biscuits. Most of them are capable of nesting indoors in wall spaces, ceiling and wall insulation, crevices in furniture etc. Most also tend sap-sucking bugs like aphids and scale insects on plants. The protected bugs produce sweet secretions attractive to the ants, and can be vectors of plant bacterial, fungal and viral diseases. When dense populations of ants nest in the ground they can induce damage to soil structure, causing crops to fall over, and they can undermine the foundations of paths and small buildings. Several species are attracted to plastics and cause damage to irrigation and electrical installations. Several house fires in northern Australia are believed to have been caused by short-circuiting resulting from ant damage. Some ‘”tramp” species have painful stings, while others bite and then spread or spray venom from the tip of the abdomen, so as to irritate the bite wounds.
Several native ant species are also injurious to human enterprise. Most prominent are the Australian Bulldog and Jumper Ants. There are many known cases of severe human allergic reactions (even death) due to their stings. Other troublesome native ants include some of the Meat Ants and the Green Weaver Ant.