The 2 most common variety of Ant encountered in the UK are The Garden or Black Ant (Lasius niger) and The Tropical/Pharaoh’s Ant (Monomorium pharaonis)
The Garden Ant (of which the Flying Ant is part of the colony) has a black segmented body, the workers are 5mm in length and the queen is 15mm long and brown in colour. Their nests are found in soil, lawns and close to buildings.
The Pharaoh’s Ant, which is of tropical origin, is a smaller species; the workers are only 2mm long, the queen 5mm long and both are yellow brown in colour, sometimes with a darker abdomen.
The Garden Ant is found throughout Britain and will nest in gardens and around buildings often entering premises in search of food. The Pharaoh’s Ant by contrast requires a very warm environment and has adapted itself to life in large heated buildings such as hospitals, hotels and flats.
The Garden Ant is a nuisance because of its foraging habit but it does not carry germs or spread disease. Garden ants are attracted to sugary food; the presence of ants in food although unpleasant, does not in itself constitute a health risk.
Pharaoh’s ants are of greater significance as they carry harmful germs which they pick up when feeding on decomposing food, faecal matter and when coming into contact with drains and hospital dressings. They are a particular problem in hospitals and are difficult to eradicate.
It is essential when dealing with an ant infestation to first identify the correct species before trying to eradicate them, as they have different colony systems. In some cases, if a colony is scattered they can rebuild it very quickly, potentially giving you a larger problem than you had initially.