MUTATION IN RATS

FAST MUTATION IN RATS:

An increasing number of rats in areas of the west of England are mutating to become more resistant to commonly sold poisons, a university study has found.

Scientists at Huddersfield University said about 75% of rats in Bristol, Gloucestershire and Wiltshire had built up a resistance.

The most serious mutations have affected rats in Bath and Wiltshire.

Experts have blamed the rise on the incorrect use of poisons where dosages which are too low have been used.

Rats which are resistant to the poison are fattened up by the bait. Those that survive then mate with other resistant rats, allowing a generation of rats resistant to existing poisons to build up.

Mutations have previously been found in many parts of the UK but the Huddersfield University study is the first time the extent of resistance has been measured in the West.