Mutant rats could be on the rise

A study is underway to find out how many rats here have mutated and become resistant to poisons.

Scientists at Huddersfield University fear many rats in Bristol, Gloucestershire and Wiltshire have become immune to poisons, because they have been given doses that are too low to have an affect.

Dr Dougie Clarke from the University is leading the study, he told Heart what could happen if the problem is not sorted out:

''You are effectively giving them free food. That is a waste of money, time and the rat population will potentially just increase. So birds of prey, you've got domestic cats etc that could catch the rats and eat them and therefore they would get secondary poisoning from them.''

The study is looking to take around 600 samples from across the country and there is a warning that within 10 years all rats here could be resistant to poisons if nothing is done.