Ants

Insecta Hymenoptera

Most Active

AntPeakSeason

Habits

  • Often become a nuisance in homes during dry weather when they search for water, or when nests are disturbed after rain
  • Winged ants swarm in late summer and spring, often after rain
  • May form trails to food locations
  • Many species active during the day (carpenter ants mostly forage at night)

Life cycle

  • Eggs are small and ovoid.
  • Larvae are whitish grubs, narrower towards the head.
  • Pupae are similar to the adult, but soft, creamy-white and inactive.
  • The adult stage consists of several types, each with a different function, e.g. queen (female), males, workers (sterile females).
  • Immature stages are cared for by the adults.
  • Development from egg to adult may take from 6 weeks upwards.
  • In many species, at certain times of year large numbers of winged males and reproductive females are produced, swarm and mate. New colonies are formed by the fertilised females.
  • In other species, several queens may exist within one colony. These occasionally leave, with a number of workers, to form a new colony.

Damage

Ants are primarily a nuisance pest, although they do have the potential for disease transmission. Some species bite or sting. The mounds formed by nests in lawns are considered unsightly, and the tunnels may cause the grass to die. Ants found “infesting” plants are actually farming plant-sucking bugs (e.g. aphids or scale insects). The ants consume the sweet honeydew produced by the aphids, and in return protect the aphids from predators. In this situation the aphids should be treated, which will result in control of the ants.

Control

  • Focus on excluding ants from buildings. Treat cracks, crevices and entry points with granules or barrier sprays. Treat nests if possible.

Prevention checklist

  • Reduce available food: keep food in sealed containers; dispose of garbage regularly; ensure the house (particularly kitchen) is clean, including under appliances; place pet food bowls in a tray of water; ensure house plants are free of sap sucking insects.
  • Reduce available water: repair leaky taps and pipes; remove unnecessary containers of water.
  • Reduce entry points to a building: repair holes, cracks and gaps in walls and skirting boards.
  • Inspect plants, equipment, etc for ants before bringing indoors.
Identification Description Nesting habits Feeding habits Active

White-footed house ant, Technomyrmex albipes
image 2.5 – 3 mm Black Indoors: wall cavities, behind skirtings, under kitchen cupboards Outdoors: rockeries, paths General feeder, but prefers sweet substances Year round, but peak seasons of Summer and Autumn

Odorous house ant, Tapinoma minutum
image 2 – 3 mm Brown to dark brown Distinct odour when crushed Indoors: in walls, under stoves and cupboards, subfloor voids Seldom swarms General feeder, but prefers sweet substances

Carpenter ant, Camponotus sp.
image 7 – 12 mm Jet black / reddish-brown Decayed/moist wood, soil, mostly in bushy areas Farms aphids General feeder (including dead and live insects), but prefers sweet substances

Argentine ant, Linepithema humile
image 1.5 – 3 mm Light brown to brown Very active Exposed soil, rotting wood, treeholes Moves indoors in wet weather Seldom swarms General feeder but prefers sweet substances

Pharaoh’s ant, Monomorium pharaonis
image 1.5 – 2 mm Light yellowish brown to darker brown Indoors: wall voids, foundations, heating ducts Large colonies, several nests; seldom swarms General feeder but prefer meat and fatty foods

Singapore ant, Monomorium destructor
2 – 3 mm Light brown with darker posterior abdomen In/around buildings: wall cavities, skirtings, paths. Attracted to plastics in electrical & irrigation equipment General feeder, but prefers animal materials to sweet substances

Coastal brown ant, Pheidole megacephala
1.5 – 2.5 mm Light yellow/brown to brown Indoors: brickwork, cavity walls, skirtings Outdoors: paths, rockeries Prefers animal materials – meat, fat, grease, dead insects