This is one of The Dipping Pool poems.
The Yellow Storm*
For two days there had been a strange calm.
Trees, ragged and half-stripped, held still in the damp, warm October air.
On the third day it was dark at nine in the morning.
High up, the wind was moving fast, clouds heading east.
The whole sky was grey – pale, dirt grey, like the last water from washing slates at the quarry.
She came out of the cottage into a sick, yellow light.
Beyond the hills the air was darker, the sun a perfect circle
and she could look right at it through the thick air.
Clouds passed over its surface, the diseased pink of watery blood.
But near the ground there was no breeze.
There was no sound of birds;
not even a robin rattled its warning as she walked towards the cowshed.
Suddenly, in formation, their leader paler than the rest, came the rats
pouring from a hole in the barn door.
Backs arched, on quiet feet, looking neither left nor right,
nor for once seeking the shadows
(for they seemed to sense nothing would dare confront so strange a thing)
across the cobbled yard they moved, a silent wave, disturbing the air.
Hundreds of them, leaving the barn behind, bound for the river.
*The passage with the rats happens just before an unnatural weather event in the book, the yellow storm. It comes from family lore through my mother, whose family farmed a small holding near the river at Cwm Einion near Eglwysfach, Ceredigion.