The danger arises when potentially poisonous plants and your chickens are not free to choose their snacks. Chickens in these situations will eat toxic plants out of boredom or lack of choice when it is the only option available.
The chickens are always a little frantic as I begin to clean, wondering what’s happening to their little world, but they’re all so happy to be out in the spring sun with a light breeze blowing that no one complains too much.