I was always told, by shepherds I have to say, not vets,

that each pellet in sheep droppings is the result of a single cud.
ie Bring up/chew/swallow. One pellet, one mouthful.
So some sheep don't rest enough and chew the cud properly, an important part of the day in sheepland. Perhaps stressed or flighty or generally off colour, or on a new feed?
I am always studying their droppings as I walk about, it tells you so much about feeding and worming requirements.
Important part of the job.
Snigger-ye-not!