My 4 week old chicks are telling me they want to have a dust bath. They are trying to do it in the wood shavings in their brooder. I'd like to start slowly exposing them to real dirt but there's no dry dirt here because of all the rain and snow we've been getting. The forecast says more and more is on the way. Where is spring??? Is there a substitute for a dust bath other than the woodchips they've been using?