Despite the dramatic headline, this has nothing to do with dust bathing causing fires. The relationship is all in the re-use. We heat our home with wood and collect the fireplace ash to use in the barn for making dust baths for the birds. The enjoy the ash and combined with a little sand, it is a great way for them to clean themselves and keep the biting pests at bay.
Here you can see Gladys, one of our Buffs enjoying one of the pans we set out for them. There is a line waiting for the bath! It is funny to see chickens line up to take turns, and they seem to do it on a regular basis for baths and nesting boxes, though never for food. When it is dinner time, it is all hands (wings?) on deck at the same time.