A PLAGUE of “mutant super rats” is fending off attempts to kill them by consuming poison as if it were just food, experts have warned.
Pest controllers said that efforts by Edinburgh residents to rid their homes of rats was only making the vermin more resistant to toxins.
Researchers have been studying the DNA of pest controllers’ victims and have found evidence that “super rats” are growing in numbers.
A team from Huddersfield University said the poison-resistant rodents were capable of consuming anticoagulant pellets “like feed”.
Now pest control firms have joined forces to warn people across the Capital to stop trying to solve rat problems themselves, as venom bought in shops was often useless.
Richard Moseley, of the British Pest Control Association (BPCA), said: “Normal rats are being killed off by poison, so these resistant species are taking their place – it’s only natural that their numbers are expanding. They eat poison like feed – you might as well be leaving out grain for them.
“Rats carry and spread diseases, so if their populations are left unchecked there can be a big public health risk. I would urge people worried about infestations to seek professional advice.”
It is thought that tough financial times are prompting residents to swerve calling in the experts to deal with rat problems and instead are snapping up cheap poison from hardware stores.
Pest controllers in the Capital said there was clear evidence that once tried-and-tested methods were these days proving ineffective.
Gavin Lindsay, owner of Anglo Scottish Pest Control, said: “We get a lot of calls from people who have tried to take the matter into their own hands, not realising that the main rat poisons on the market are having less and less effect.
“It may kill one or two rats, but the others will either be resistant to it or have learned to avoid it in the first place.”
The 50-year-old from Morningside added: “People who live in rural areas and on farms often have the most problems, but some areas of the New Town which don’t have proper wheelie bins also get a lot of rats.”
During last year’s bin collection crisis, pest control companies in the Capital reported a 30 per cent surge in the number of call-outs to deal with rat infestations.
Rob Simpson, managing director of Basis Prompt, which registers qualified pest controllers, said: “If people try to deal with issues themselves, or bring in unqualified controllers because they are cheap, infestations could get out of hand.
“It’s easy to get out of your depth when trying to control pests of all kinds as their treatment is often specialised.
“But that is particularly the case with these so-called ‘super rats’, which are resistant to routine poisons.”
WE’VE GOT THIS, SAYS COUNCIL CHIEF
THE city council offers its own pest control service, and insisted the rat population was under control.
Between November 2011 and November 2012, the service received 575 call-outs regarding rats, compared with 436 in the following 12 months.
Environment convener Councillor Lesley Hinds said: “It’s no surprise that pest control companies have claimed again that they’re seeing an increase in demand for business, but we can reassure people that the vermin population is largely stable and under control. Our figures show a year-on-year decline in the number of calls from the public regarding rats – last year’s figures had fallen by over a third compared to 2010.”