We are having a very wet spring, and laid some straw on the walkway to our chicks. They are in my husband's dry heated shop. There was one flake of straw that had some mold (we've removed that since we realized that). We are concerned about mold spores that may have come in on our shoes, particularly since we'll be getting new chicks in a few days. I'm hoping it's too dry in there for it to be a concern, but we certainly don't want to compromise our chickens.