Ghost ant Tapinoma melanocephalum
- Size
- 1.3 to 1.5 mm
- Colour
- Dark brown head and thorax; the abdomen and legs are milky white, so only the head seems to move.
- What you notice
- Tiny ants that almost vanish on a pale counter.
- Where
- Kitchens and bathrooms, nesting in wall voids, between cabinets and skirting boards, and in potted plants. They like sweets and need moisture.
- Bite or sting
- Not known for biting people.
- What to do
- Keep sweet food in containers that seal and fix leaks. Follow the trail back and bait it near the nest.
Pharaoh ant Monomorium pharaonis
- Size
- 1.5 to 2 mm
- Colour
- Yellowish to light brown or reddish, with a darker, blackish abdomen.
- What you notice
- Tiny pale ants in long lines, often somewhere warm.
- Where
- Warm, humid hidden places near food and water: wall voids, appliances, even between folded linen and clothes.
- Bite or sting
- Not known for biting people; the problem is that they get into food and anything left open.
- What to do
- Do not spray them. Repellent sprays make a colony split into several new ones, and the problem comes back bigger. Non-repellent baits placed on their trails are what works.
Bigheaded ant Pheidole megacephala
- Size
- About 2 mm; the big-headed workers 3 to 4 mm
- Colour
- Reddish-brown. A few larger workers have heads far too big for their bodies.
- What you notice
- Small piles of soil pushed up along the edges of walkways and cracks in concrete.
- Where
- In soil: under slabs, pots and bricks, along the base of the house and the edges of lawns and paths.
- Bite or sting
- Not known for biting people; the problem is their numbers.
- What to do
- The nests are outside, so treatment goes round the base of the house, the lawn edges and the paths, not just the kitchen.
Crazy ant Paratrechina longicornis
- Size
- 2.3 to 3 mm
- Colour
- Dark brown to blackish, with very long legs and very long antennae.
- What you notice
- Fast, jerky running in every direction instead of neat trails.
- Where
- Nests outdoors in rubbish, rotting wood, soil and plant cavities, and comes indoors for food.
- Bite or sting
- Not known for biting people.
- What to do
- Seal gaps round pipes and doors and take away food left out. Indoors, baits and spot treatment.
Tropical fire ant Solenopsis geminata
- Size
- 3 to 5 mm
- Colour
- Orange to brown body with a brown head. The larger workers have almost square heads.
- What you notice
- Swarms that pour out when the soil is disturbed, from loose mounds and soil workings in sunny ground.
- Where
- Open, sunny ground: yards, lawns, roadsides, the edges of gardens.
- Bite or sting
- A painful sting, repeated, that burns and then swells red. In some people it causes a severe allergic reaction.
- What to do
- Keep children and pets off the mounds. Baits taken back to the nest are how colonies are killed. Anyone with swelling beyond the sting site or trouble breathing needs a doctor.
Weaver ant hantik Oecophylla smaragdina
- Size
- 4 to 10 mm
- Colour
- Orange to reddish-brown. Big workers are 8 to 10 mm; smaller ones about half that.
- What you notice
- Nests of living leaves stitched together with silk, high in trees such as mango.
- Where
- In trees, not usually indoors.
- Bite or sting
- A sharp bite, and they spray formic acid into it. They do not sting.
- What to do
- Usually best left: they hunt other insects in the tree. A nest over a doorway, a path or a play area is the exception.