There are over 4000 known species of ants in Australia, however, only a few of these (mostly introduced species) are considered pests. Ants can be considered pests when they enter or cause damage to buildings, landscapes and soil structures.
Pest ants often nest in and around buildings, mostly congregating in food preparation areas, and have the potential to spread disease. Ants entering homes and buildings can cause considerable concern and annoyance to the occupants. Ants can also cause considerable damage to buildings through the removal of small amounts of soil from concrete and brick paving eventually leading to a building subsiding and cracking.
Outside, ants remove planted seeds from the soil causing less germination and can nest around the bases of small shrubs and trees, resulting in undermining which can eventually topple them.
Contrary to common belief ants are not related totermites, and cannot damage sound timber.
Colony sizes vary and nests can range from a few dozen ants, to millions of individuals. Larger colonies consist mostly of sterile wingless females which form castes of ‘workers’. Workers may be specialised, for example into minor and major (or soldier) castes. These perform specific tasks, such as feeding and caring for the immature forms, and appear physically different. Nearly all ant colonies have fertile males called ‘drones’ and one or more fertile females called ‘queens’.