For pest control firms, rats are one of the commonest forms of pest problem that they are called out for. For many, rat poison is the ‘go to’ solution for dealing with an infestation, but its use may be becoming less effective according to recent media reports.

First reported by the Metro and then picked up by other national newspapers, reports suggest that populations of poison-resistant rats are increasing. Not only that, but their geographic spread is widening too, with such rats being found as far afield as Sussex, Kent and the West Country.

Dubbed ‘mutant super rats’ by the press, the rodents have a tolerance to rat poison that is believed to be caused by a natural genetic mutation. The reason for their growing numbers can be easily explained by the process of natural selection; those with the poison-resistant gene are more likely to survive longer and produce greater numbers of offspring, who are in turn also likely to carry the gene.

Survival of the fittest

Speaking to the Metro, Richard Mosely of the British Pest Control Association 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.”

While the tabloid media’s assertions that Britain is being ‘over-run’ by this new breed of rat are undoubtedly an overstatement, there is no denying that the numbers of poison-resistant rats are increasing. New methods and pest control products may therefore be needed to deal with the problem.

Mosely reportedly gave his support to the use of stronger poisons, while a number of alternative methods, such as rat traps, may be effective for pest control in the UK. Such methods are already in use in areas where poison is inappropriate, and include traditional rat traps, glue traps and rat repellers.