I thought that might be it, but seems I read somewhere on here that a chicken will 'create' dust even when there's not any around. I don't know why that surprises me, I've got three boys that do that all the time!
BTW, love Montana. I'll be in Great Falls tomorrow night as a matter of fact.
I have read on this forum that chickens are 'dusty'. My first ever chicks are now 4 weeks old, and in the last week I've noticed a build up of dust in the coop. It began before I started letting them out in the run for a while on warm days (which they love), so it's not just the dust from...