Black Ants Family Name: Formicaide
Scientific Name: Lasius niger

Nests Outdoors and enters houses regularly in search for food, preferably sweet foods

Habitat
An active insect, it nests outside in grass and walls and under paving. It will forage widely in search of food, which is how it comes to enter domestic premises.

Biology and Behaviour
Workers dark brown-black, queens mid brown. Workers 3-5mm long, queens (characterised by 2 pairs of membranous wings, fore and hind wings hooked together) 15mm long. Individual ants are responsible for specialised duties within their community. The worker ants (sterile females) build the nest, look after larvae, and forage for food. The queens (fertile females) remain mainly in the nest, mating with fertile males. Swarms involve large numbers of ants but only tend to persist for 2-3 hours. The males die after mating, but the females shed their wings and burrow in the ground where they overwinter.

 

Pharaoh Ants
Family Name: Formicidae
Scientific Name: Monomorium Pharaonis

Widely distributed and need warm and humid conditions. They feed on meat, cheese, fat, sugar, Honey and jam. In hospitals they feed of blood and intravenous diet fluids. Dead insects and mice droppings can also provide a food source.

Habitat
Infestations can be found in a wide variety of locations including residential blocks, hotels, hospitals, zoos and on board ships. In warmer climates infestations can be found outside. The insects are located in the fabric of buildings (wall voids, windows etc.), plants and sterile supplies. Infestations may be spread by way of service ducts (e.g. heating and electrical conduits). The ants forage for water around sinks and areas of condensation.

Biology and Behaviour
Workers 1.5-2mm long, yellow-brown with well-developed black eyes. Males 3mm long, black and winged. Queens 3.6-5mm long, dark red and winged. Winged Pharaoh ants do not fly. The queens can be replaced so colonies survive indefinitely. New colonies may be encouraged by disturbing the nests. These social insects live in colonies from a few dozen to 300,000 ants. The ants can survive low temperatures for prolonged periods where the works continue to forage for food. Materials may be damaged by chewing and the ants may bite children. Can penetrate plastic bags containing sterile dressings/instruments. Pharaoh ants pose a risk to health as pathogenic organisms may be transmitted as the ants feed in unhygienic places including drains, bins and wound dressings.

Argentine Ants
Family Name: Formicidae
Scientific Name: Linepithema humile

Invasive species favouring warm climates or heated environments.

Habitat
Prefer a sweet food source such as honeydew, but will also forage on proteins such as meat, insects, eggs and fat.

Biology and Behaviour.
Argentine Ants are typically brown/light brown, with an uneven thorax, 12-segmented antennae, no stinger, the workers are 3-3.5mm long. In a single colony there may be multiple queens (polygenic), and the workers interact between nests, which enables them to form ‘super colonies’. The queens can be replaced so colonies survive indefinitely. New colonies may be encouraged by disturbing the nests.