According to Environment Secretary Richard Lochhead:
"They're widespread in south and central England but have a patchy distribution between the Humber and the Scottish borders. They are destructive animals, or invasive species to use the more modern term. They can have significant negative impacts in the wild, both to biodiversity and economic interest."
They can damage orchards, cereal crops, coppice woods and bluebells, he said, and have been known to add to accident risks on roads.
Source: The Press Association