KEIGHLEY people with rat problems are being warned against using DIY measures in a bid to exterminate the rampaging rodents.

The warning has been issued by trade body the British Pest Control Association (BPCA), which says a new generation of rats has been identified that carries a genetic mutation making them resistant to conventional poison.

The findings were from a study by the University of Reading.

Dee Ward-Thompson, for the BPCA, said: "The study highlights the fact that resistance is growing in rat species across a swathe of the country.

"It also reports that rats without the genetic mutation are being killed off by poison, so the resistant species are taking their place.

"With their numbers expanding, there could be a significant risk to public health if their population is left unchecked, in both urban and rural environments."

The study reveals that so-called L120Q is the most severe form of rodenticide resistance identified to date.

Ms Ward-Thompson added: "The rise in resistance could be due to a number of factors.

"However, it is most likely the spread has been accelerated by the application of rodenticides, by amateurs such as home and business owners doing it themselves or employing an unqualified individual to try to resolve the problem.

"The clear message is that, to be effective in tackling this issue, people should not attempt to self-treat rats.

"Professional-use-only rodenticides are often more successful, but most are subject to strict legislation, so it has become more important than ever before to make sure infestations are treated by experts.

"Rats must be dealt with by those with the skills required to understand rodent behaviour and their habitat, and who know how to treat any particular strain."