A British newspaper columnist has declared war on a carnivorous New Zealand worm that has invaded the United Kingdom.

The New Zealand flatworm was discovered in Belfast in 1963 but has since spread throughout the north of the UK - including the garden of Telegraph columnist Ken Thompson.

What seems to vex Thompson is the flatworm's carnivorous diet of earthworms.

But Thompson's garden was still full of mole holes - a good sign that the UK's own critter with an exclusively earthworm diet can still find plenty to eat. "I'm still going to carry on squashing NZ flatworms, though," Thompson wrote.