Common Ant Species

Some ant species live in colonies that are supported by a single queen while others are supported by multiple queens. Although there are around 16 ant species known in Thailand, there are relatively few that we commonly found in our premises. These include:

Black House Ant

(Ochetellus)

Appearance

  • Shiny and black.
  • 2.5 - 3mm long.

Lifecycle

  • Larva hatches out of the egg as a white grub which is narrower towards the head. They are fed by the adults.
  • The larva pupates and appears creamy-white, looking similar to an adult. Sometimes they have a protective silk cocoon around them.
  • The adult emerges with the three defined body sections: head, thorax and abdomen.
  • The length of time between the egg stage and ants emerging as adults can take 6 weeks or more; it depends on a variety of factors such as the species of ant, the temperature and the availability of food.
  • Fertilised eggs become female, unfertilised become males.

Habits

  • These ants are regarded as a nuisance and scavenge in kitchens, garbage and also dog excrement, therefore potentially spreading diseases such as salmonella.
  • The most effective control measure is to find the colony and treat it.

Fire Ant

(Solenopsis spp)

Appearance

  • Queens 5/8" long. 
  • Workers 1/8"-1/4" long. 
  • Coppery–brown on the head and body, with a darker abdomen. 
  • Solenopsis has a very distinctive two–segment antennal club, which is most visible in the front view of the female reproductive ant.

Lifecycle

  • After swarming from the nest and mating, the queen searches for a suitable spot to lay her eggs. Once found, she can lay up to 125 eggs in late Spring. 
  • Larvae hatch within 8 to 10 days, and the pupal stage lasts for 9 to 16 days. 
  • Larvae feed on secretions from the queen’s salivary glands and broken down wing muscles until the first worker ants emerge. After this first batch of larvae moult into workers the queen’s role returns to egg laying – she can lay up to 1500 per day. Worker ants continue with larval care, nest building and food foraging. 
  • Fertile males are produced later in the season.

Habits

  • Foraging workers diet consists of dead animals, including insects, earthworms, and vertebrates. Workers also collect honeydew and forage for sweet food, proteins, and fats. 
  • Nest locations can be a mound of up to 40 cm or next to objects found on the ground, e.g. logs. 
  • If aggravated, these react aggressively and can inflict a painful sting, resulting in a pustule some 48 hours later. 
  • These ants are a major agricultural and urban pest, destroying crops and invading residential areas both outdoors and indoors.

Ghost Ant

(Tapinoma melanocephalum)

Appearance

  • Pale/Translucent legs and abdomen.
  • 16mm long.

Life Cycle

  • Continuous breeding colonies.

Habits

  • Feeding – indoors: sweet substances and grease; outdoors: insects that produce honeydew.
  • Nesting – indoors: small spaces, wall voids; outdoors: in flowerpots, under objects on the ground, under loose bark.
  • Locations - attracted to high moisture areas, can be found in kitchen and bathroom cabinets.
  • Colonies can occupy several different nesting sites.

Odorous House Ant

(Tapinoma sessile)

Appearance

  • Brown or black. 
  • 1/16 to 1/8 inch long. 
  • Antennae have 12 segments and are not terminated with a club. 
  • 6 legs.

Lifecycle

  • Time to adult phase of development is 34-38 days. 
  • Typically live for several years.

Habits

  • Feeding - eat most household foods, especially sugary food, eg sweets and fruits such as melon. Also eat pet food. 
  • Locations – attracted to moisture. In hot, dry environments nests can be found in house plants and even lids of toilets. 
  • Odour - produce a coconut smell when crushed. 
  • Colonies - range in size from 100-10,000.

Pharaoh’s Ant

(Monomorium pharaonis)

มดละเอียด

Appearance

  • Workers 1.5-2mm long, yellow-brown with brown abdomen.
  • Males 3mm long, black, winged.
  • Queens 3.5-6mm long, dark red in colour with wings.
  • Black eyes, 2 small segments at the pedicel.

Life Cycle

  • Multi-queen colonies.
  • Swarming can take place at any time of the year.
  • Winged adults seldom fly so rarely seen. Wings are soon lost after mating.

Habits

  • Well–defined trails are laid which are often associated with heating systems. Feeds indoors on high protein foods — meat, fats, blood, dead insects, etc.
  • Swarming characteristics — new colonies are often formed through nests that have been disturbed e.g., as a result of insecticide spray treatments.
  • Each queen produces up to 3,500 eggs in its lifetime.
  • Nest locations — deep seated in cavities in heated buildings. Often found in hospitals. Associated with humid conditions. Colonies can range from a few dozen to 300,000 individuals.

Carpenter Ant

(Camponotus pennsylvanicus)

Appearance

  • Workers: 1/4" long.
  • Queen: 1/2" long.
  • Blackish color most common but can also be black and red.
  • 6 legs.

Life Cycle

  • It takes 3 - 6years to establish a large and stable colony.
  • The life cycle of a carpenter ant is estimated to be 6 - 12 weeks from egg to adult.

Habits

  • Locations - both moist and dry wood, but prefer moist, e.g. wood dampened by water leaks.
  • Internally - excavate galleries in wood with a smooth appearance.
  • Externally - sometimes hollow out sections of trees.
  • Visibility - hunt for food mainly at night but also during the day in early spring / summer. Signs include sawdust, wet wood, or unusual noises coming from the walls.
  • Feeding - primary food is honeydew, also eat plant secretions, fruit juices and insect remains. They do not eat wood. In homes they are attracted to sweet substances, fats, grease and meats.
  • Contact - rarely come into contact with people, but if they do will try to escape. They cannot sting.

Crazy Ant

(Paratrechina longicornis) 

มดน้ำผึ้ง

Appearance

  • Dark brown.
  • 2.5 – 3.3mm.
  • 6 legs.
  • Antennae are with 12 segments and without club.

Lifecycle

  • Multi-queen colonies.
  • Colonies of crazy ants are moderate to very populous.
  • On warm, humid evenings, large numbers of males gather outside nest and may swarm about excitedly.

Habits

  • Nesting – crazy ants make their nests in a wide range of either dry or damp sites.
  • Feeding habit – omnivorous and feed on seeds, dead invertebrates, plant secretions, fruit and a range of household scraps.
  • Crazy ants are able to invade new habitats and out-compete other species of ant.

Next Steps

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