Moles.

There seemed to be a plague of moles last year. Most fields were a mass of molehills which cause several problems.
An old man named Elfet who lived in what is left of Llanafan village which now has only about six houses, took me to one of his fields and showed me how to set a mole trap. This must be done properly or you are wasting your time as moles are clever little sods with a keen sense of smell, so no soapy smell on your hands and use weathered traps.
My own field looked like the third battle of Eypres when I set my first traps but it is fine now.
I caught nine moles and have just rid Elfet's field of his.