Ants are members of the family Formicidae within the order Hymenoptera, the insect group that also includes bees and wasps. Australia is home to approximately 3,000 known ant species, making them one of the most diverse and widespread insect groups in the country. Ants are highly organised social insects that live in structured colonies, usually within permanent nests. Nesting sites vary by species and may occur in soil, wall cavities, roof voids, timber, under rocks or within garden beds. Colony sizes range from a few hundred individual to many thousands, depending on the species. Unlike many other insects, ants are adapted to feed primarily on liquids. Solid food particles are often carried back to the nest and processed with moisture and saliva before being consumed or shared among colony members. This behaviour allows them to exploit a wide range of food sources in and around buildings. Because of their adaptability, ants are among the most commonly encountered insects in residential and commercial environments. They are frequently seen along foundations, inside wall cavities, in kitchens and pantries, within lawns and gardens, and in decaying timber. As a group, ants are regarded as one of the most evolutionary successful insect families due to their complex social systems, cooperative behaviour, and ability to thrive in varied environments.

Ants have a clearly segmented body divided into three main sections: the head, thorax and abdomen. One of the most distinctive features is a narrow "waist" between the thorax and abdomen. This waist is formed by one or two small segments called the pedicel, which may appear as raised bumps or nodes. The number of shape of these nodes are important characteristics used to distinguish between different ant species. The head contains a pair of compound eyes and a set of elbowed (bent) antennae, which are a key identifying feature separating ants from termites. Some species also possess small simple eyes (ocelli) although these are not always obvious. Most worker ants are wingless. However, reproductive males and queens develop wings during the breeding season. When present, the wings are clear and membranous, with the front pair noticeably longer and broader than the hind pair. After mating, queens typically shed their wings before establishing a new colony. These structural characteristics; particularly the narrow waist, elbowed antennae, and body segmentation; help differentiate ants from other common insects found in and around buildings.

Metamorphosis Ants undergo complete metamorphosis, developing through four distinct life stages: egg, larva, pupa and adult. Eggs are small and oval in shape. The larva that hatches is a soft, legless, whitish grub that relies entirely on adult workers for feeding and care. After several moults, the larva enters the pupal stage, a transition phase during which it develops into an adult. Pupae are typically creamy-white and inactive; in some species they are enclosed within a silk cocoon. Once development is complete, the adult ant emerges and gradually hardens and darkens over several hours or days. The time required for development from egg to adult varies widely depending on species, temperature, food availability and environmental conditions, and may range from approximately six weeks to several months. Castes Ant colonies are organised into three distinct castes: Male Ants: Males adults are winged and are produced for the sole purpose of reproduction. After mating, males usually die shortly thereafter. Queens (Reproductive Females): The queen is typically the largest member of the colony. She begins adult life with wings and participates in a mating flight, after which she sheds her wings and establishes or joins a nest. In many species, a colony has a single queen, while others may contain multiple reproductive females. Once mated, a queen can lay fertilised eggs for many years and may live for over a decade under favourable conditions. Workers: Workers are sterile, wingless females and form the majority of the colony. They are responsible for foraging, nest construction and maintenance, caring for eggs and larvae, defending the colony, and feeding other castes. In some species, workers vary in size, with larger individuals sometimes referred to as soldiers. Worker lifespan is generally around one year, although this can vary. Reproduction Reproduction typically involves a seasonal mating flight, during which winged males and females swarm and mate in the air. Fertilised queens then shed their wings and seek a suitable nesting site to establish a new colony. Unfertilised eggs develop into males, while fertilised eggs develop into females (workers or future queens). Not all species rely on large swarming flights. Some ants mate within or near the original nest. In certain species, new colonies are formed by a process known as budding, where one or more queen/s leave a parent nest accompanied by a group of workers to establish a nearby colony. This behaviour can allow infestations to spread gradually through wall cavities, garden beds and neighbouring properties, particularly in species that maintain multiple interconnected nests.

Most ant species establish permanent or semi-permanent nests, although relocation can occur if environmental conditions change or the colony is disturbed. Nests are commonly constructed in soil, beneath paving, within wall cavities, roof voids, decaying timber, garden beds or under rocks. Some species form extensive underground tunnel systems, while others create interconnected satellite nests spread across a property. Worker ants leave the nest to forage for food and water. Once a reliable food source is located, workers often establish clearly defined foraging trails between the nest and the resources. These trails are typically maintained using chemical signals known as pheromones. Trail-marking pheromones allow other workers to follow the same path efficiently. In addition to chemical communication, ants use a combination of sensory cues including touch (via their antennae), taste ( through food exchange), vibration, and in some species, vision.

Ants are commonly regarded as nuisance pests when they establish nests close to homes or begin foraging inside buildings. Their presence is often noticed when worker ants form visible trails across floors, walls, benches, or around entry points such as windows, doors and foundations. These trails occur when ants locate a reliable food source and recruit other workers from the colony using chemical scent markers. Outdoors, ants may build small soil mounds or excavate material from beneath paving, paths, garden edging and building foundations. These excavations can create unsightly areas in lawns, garden beds and along pathways, and in some cases may contribute to minor movement or cracking in older paved surfaces. Around homes, ants may also nest in wall cavities, roof voids or under flooring, where they remain largely hidden but continue to forage inside the building. In gardens, some species may disturb soil around seedlings or consume seeds, which can affect newly planted plants. Ants are also commonly associated with plant-sucking insects such as aphids and scale insects. By feeding on the sugary honeydew produced by these insects, ants may protect them from natural predators, which can allow plant pest populations to increase. Ants can also present hygiene concerns in food preparation and storage areas. As scavengers, they frequently move between outdoor environments, waste areas, and indoor food sources. During this process they may carry bacteria or other microorganisms on their bodies or within their digestive systems. While ants are not primary disease carriers, their movement through kitchens, pantries, rubbish areas and other contaminated locations means they have the potential to spread unwanted microbes onto food or food-contact surfaces. Some ant species are also capable of biting or stinging when disturbed. Although most bites or stings cause only minor irritation, they can be uncomfortable and may be more serious for individuals with sensitivities or allergies. For these reasons, ants are widely considered pests when they invade homes, gardens or commercial premises.

Effective ant management begins with a detailed inspection of the property, Identifying where ants are nesting, where they are feeding and the routes they use to travel between these areas is essential for successful control. Ant trails often lead back to the nest, and following worker ants, particularly those carrying food, can sometimes reveal the nest location or indicate the general area where the colony is established. Where a nest can be located, direct treatment of the nesting site often provides the most reliable and long-term control. Nests may be found in soil, beneath paving, inside wall cavities, roof voids, timber structures or garden areas. Depending on the situation, professional treatments may involve applying targeted products such as residual surface sprays, insecticidal dusts, foams or specialised treatments designed to penetrate cracks, crevices or hidden voids where ants are nesting. In situations where the nest cannot be accessed directly, treatment may focus on the routes ants use to travel between the nest and food sources. Residual insecticide treatments may be applied along ant trails, entry points, cracks, expansion joints and other structural gaps where ants are active. These treatments form a barrier that disrupts foraging activity and helps prevent ants from reaching food sources inside buildings. Baiting systems are another important method used in professional ant management. Ant baits contain attractive food materials combined with a slow-acting insecticide. Worker ants collect the bait and carry it back to the nest, where it is shared with other colony members, including the queen. This transfer of bait through the colony can lead to a gradual reduction or elimination of the nest. Different ant species may prefer different food types, such as sugary, protein, or oil-based baits, so selecting the correct bait is an important part of effective control. Because ant nests may be located both inside and outside the building, successful management often involves treating multiple areas of the property to interrupt the colony's access for food and shelter.

Good hygiene and environmental management play an important role in reducing ant activity around homes and buildings. Ants are highly adaptable scavengers and are attracted to readily available food and water sources. Limiting these resources can significantly reduce the likelihood of infestations. Indoors, food preparation and storage areas should be kept clean and free of crumbs or food residues. Kitchen benches, cupboards, drawers, floors, tables and appliances are common areas where food particles can accumulate and attract foraging ants. Food should be stored in sealed containers and dishes or food utensils should be washed soon after use rather than left for extended periods. Rubbish bins should be kept clean and sealed and spills should be cleaned promptly. Pet food bowls should not be left out overnight where possible, as they can attract foraging ants. Outside the building, removing potential food sources can also help reduce ant activity. This may include keeping outdoor eating areas clean, rinsing drink containers before disposal and ensuring pet feeding areas are regularly cleaned. Garden areas should also be monitored for sap-sucking insects such as aphids and scale insects, as these insects produce honeydew that attracts ants. Controlling these plant pests can reduce ant activity around vegetation close to the home. Reducing nesting opportunities can also help discourage ant colonies from establishing close to buildings. This may involve sealing cracks and gaps around doors, windows and building foundations, repairing damaged seals and removing debris or timber stored against the structure where ants may nest. Combining good sanitation, environmental management and professional treatment when required provides the most effective approach to long-term ant prevention and management.