HAMPSHIRE residents living and working in high-rise flats, student halls and hospitals are being urged to be cautious of a small tropical insect that can "potentially spiral out of control".

Pharaoh ants are tiny, but can create huge colonies that will split if threatened and can potentially spiral out of control, says the British Pest Control Association (BPCA).

Residents of large multi-occupancy buildings across the county are being urged to understand the risks of the pest.

In the UK, the tiny insects will only be found in large centrally-heated buildings such as high-rise flats, student halls and hospitals.

Specialist products can effectively control the heat-loving insects – which are frequently found in the boiler rooms of interconnected buildings and, quite commonly, trailing down surfaces close to high heat sources such as ovens - but training and knowledge are key to tackling a nest of Pharaoh ants.

Pharaoh ants are around 2mm in length, yellow or light brown, almost transparent, ant.

Due to its tiny size, the insect does not bite unlike other ant species.

Natalie Bungay is Technical Manager at BPCA. She said: “Pharaoh ant nests can vary in size, but they can grow to massive proportions, with research finding nests containing 50,000 workers and 100,000 ants in the young stages.

“Only 5-10 per cent of workers forage for food, so a trail of Pharaoh ants down the face of a wall or machine is just a small part of the picture.

“The workers may respond to danger by ‘budding’ - sometimes referred to as ‘satelliting’ – and will move pupae and young larvae away from the original colony, which can lead to the ants spreading throughout a building or complex, and the infestation spiralling out of control.”

Professional pest controllers should always be called in to tackle an infestation of Pharoah ants as specialist products and careful surveying are required for successful treatment.

Natalie added: “A hormone bait can be used to sterilise queens and prevent larvae from developing, but this system can mean controlling the infestation could take around four months.

“Newer, in-depth surveying and gel bait products mean control can be achieved within two or three weeks, but a carefully planned and implemented strategy, delivered by a professional pest controller, is the key to success.”