The foraging habits and degree of specialisation of ants vary considerably. Mostly, they are opportunistic generalists, preying on or foraging for any available food source. Such an omnivorous diet may include seeds, nectar, arthropod prey, carcasses, and carbohydrate rich exudates from specialised plant nectaries or honeydew from plant-feeding insects such as leafhoppers or aphids (Hemiptera) or lepidopteran caterpillars. However, there are more specialised species whose nutritional requirements are obtained primarily or exclusively from seed harvesting, farming other insects or fungi, or as predators of particular invertebrate species. Ants are often a dominant insect group in many terrestrial habitats thus playing a key role in the functioning of ecosystems. They are important in the seed dispersal of many plants via seed collecting, they aid the maintenance of soil health and fertility and, as largely general scavengers and predators, they are integral to the regulation of many arthropod populations. In addition, they are a vital food source for many invertebrate, bird, reptile, and mammal species. Because of their ecological importance, the use of ants as tools for environmental monitoring has been developed over recent years.
Camponotus thadeus, one of the more striking Australian ants.