Mouldwarps, Misconceptions, and Mass Extermination

Only the other day, we were marvelling at the sheer number of molehills littering the fields this year. Which, naturally, means an abundance of moles—or, if one prefers their grander, more traditional name, “mouldwarps,” an old English term meaning “earth-thrower.”

I remarked that their presence must indicate rich soil teeming with earthworms. The so-called “gentlemen in velvet” aerate the earth, mitigate flooding, and play a vital role in the soil’s ecosystem. Surely, they pose no threat to livestock? But no, the immediate response was that molehills reduce grazing—by as much as 25%, according to a figure found on Facebook, so maybe take that with a pinch of salt. Then there is the matter of their tunnels, which, it is claimed, lead to broken legs in horses and livestock.

Sheep, it seems, are at risk of listeriosis if they consume dirt from molehills. Contaminated winter feed can become unpalatable or even toxic for dairy cattle. And so, moles stand condemned, though one cannot help but suspect a whiff of inherited prejudice. Why else would mole catchers feel the need to hang their corpses over fences like some grotesque warning sign? Could it be a subtle message to surviving moles to pack up and leave? A convenient way for the mole-catcher to count his spoils and charge accordingly? Or simply a means of demonstrating his prowess?

Once upon a time, the local mole-catcher was quite the figure. Often a charming rogue, he supplemented his earnings with a little poaching and was a veritable encyclopaedia of countryside lore. His craft was a well-guarded secret, and it was widely believed that he would always leave a few moles behind—ensuring a steady supply of work for himself in the future.

Official mole control began in 1566, when the so-called Little Ice Age threatened England’s food supply. Queen Elizabeth I, ever the pragmatist, passed “An Acte for the Preservation of Grayne,” which remained in force for three centuries. The law offered bounties for exterminating an eclectic mix of agricultural “vermin,” including hedgehogs and kingfishers. Some parishes paid a halfpenny per mole, while others appointed mole-catchers on contracts lasting up to 21 years. In addition to their wages, these men made a tidy profit selling the pelts, highly prized for waistcoats and gloves¹CASTELLANO, KATEY. “Moles, Molehills, and Common Right in John Clare’s Poetry.” Studies in Romanticism, vol. 56, no. 2, 2017, pp. 157–76. JSTOR, http://www.jstor.org/stable/26602996. Accessed 24 Mar. 2025..

By the early 20th century, farmers had discovered a more efficient method: feeding worms laced with strychnine to moles. The only drawback was that strychnine does not conveniently degrade once an animal has died. Anything consuming a poisoned mole—a bird of prey, a dog—could also succumb²Another Bird Blog. (2018). Underground And Overground. [online] Available at: https://anotherbirdblog.blogspot.com/2018/06/underground-and-overground.html?m=0 [Accessed 23 Oct. 2021]. .

In 1963, when Parliament debated banning the poison, a minister assured the House of Commons that moles, “strangely enough,” did not exhibit “the same symptoms of pain” as other creatures. This, apparently, justified their continued poisoning. The law duly banned strychnine for mice and rats but granted moles an exemption, as no better alternative existed.

Thus, for decades, British farmers collectively purchased over 50 kilograms of strychnine annually—enough to wipe out half a billion moles. This practice endured until 2006, when modern pesticide regulations finally saw sense and phased out the poison.

• 1
  CASTELLANO, KATEY. “Moles, Molehills, and Common Right in John Clare’s Poetry.” Studies in Romanticism, vol. 56, no. 2, 2017, pp. 157–76. JSTOR, http://www.jstor.org/stable/26602996. Accessed 24 Mar. 2025.
• 2
  Another Bird Blog. (2018). Underground And Overground. [online] Available at: https://anotherbirdblog.blogspot.com/2018/06/underground-and-overground.html?m=0 [Accessed 23 Oct. 2021].