Pest control - Ants
Types of Ants in the UK
There are about 50 species of ant found in the UK. Two species are commonly found as pests in buildings:
The Black Garden Ant
has a black segmented body, the workers are up to 5mm in length and the queen is 15mm long and brown in colour.
The Garden Ant is found throughout Britain and will nest in soil, lawns and close to buildings. It is the only native British ant which regularly enters houses in search of food, although they do not normally nest indoors.
The Pharaoh's Ant
is a smaller species; the workers are only 2mm long, the queen 5mm long and both are yellow in colour.
Along with the similar sized and shaped, but blackish, Argentine ant they are of tropical origin and can only live in heated buildings in the UK.
The Pharaoh's Ant requires a very warm environment and has adapted itself to life in large heated buildings such as hospitals, hotels and flats.
What is their significance?
The Garden Ant is a nuisance because of its foraging habit but it does not spread disease. Garden Ants are attracted to fatty or sugary food.
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.
What is their lifecycle?
The Garden Ants mate in flight when winged males and females swarm between mid July and mid September. After mating the male dies and female loses her wings and buries herself in the soil over the winter.
In late Spring the female lays eggs which hatch into white larvae in 3-4 weeks. The larvae are fed by the queen and when fully grown pupate. The worker ants which emerge from the pupae feed new larvae and the queen. The life cycle is complete in two months and in favourable conditions the nest may persist for several years.
In contrast the Pharaoh's Ant develops several colonies within each nest and many queens. As the old nest becomes overcrowded new colonies are formed by eggs and larvae carried by adults and workers.
The life cycle is the same as that of the Garden Ant but the Pharaoh's Ant, which favours heated buildings, is not affected by seasonal changes. The ants' ability to form many colonies make them difficult to control.
How can they be controlled?
There are several measures you can take to control Garden Ants:
- Identify and destroy the nest using boiling water or a proprietary insecticidal dust or spray around the nest and opening in buildings.
- Ensure that sugary foods are kept in sealed containers and all food spillages are cleared up.
- An infestation of Pharaoh's Ants must be professionally treated.