Experts have warned that a new breed of 'super rodents' could pose a threat to human health.
In the last 20 years, almost all of the mice and rats in the UK have gradually developed a resistance to a common type of poison which is used to exterminate pests.
Around 95% of house mice and 78% of rats now possess genes which mean they can tolerate poisons known as anticoagulant rodenticides that normally kill vermin by preventing blood clotting.
