Cecal droppings happen about every 10 droppings and are perfectly normal. If it's just occasional, then that may be all it is. Particularly if every one is acting normally, eating, drinking, etc.
https://the-chicken-chick.com/whats-scoop-on-chicken-poop-digestive/
If you have a vet that will do a fecal test for you, that will tell you if it's parasites or not. Some vets that see your other animals may be willing to do the test for you, and it's usually not terribly expensive, some vets refuse to test a chicken. A phone call to ask cost nothing.
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