The number of rat infestations in the most deprived inner-city areas increased by 25% last year, according to new figures.
The figures, published by Pest.co.uk, shows lockdown caused rats to migrate from city centre commercial areas to inner city residential areas.
It also warned that nearly three-quarters of rats in the UK carry a resistance gene to popular rodenticides. In some areas, a fifth of the rat population have two different genes which makes them 'super' resistant to traditional pest control methods.
Jenny Rathbone, pest controller at Pest.co.uk, said: 'Lockdown is presenting a serious challenge for pest controllers, none more so than where financial cuts and social distancing is hampering local authority departments in their ability to tackle rat populations.
'This is not only a funding issue – the population of rats is growing, and the ability to control them with traditional means is decreasing as 74% of UK rats have been shown to carry immunity to popular poisons.'