I don't know if a dustbath is something they NEED. All birds, not just chickens, have an instint to dust themselfs. It provides relief from bugs and helps keep themselves clean. They will create their own area in the yard if one is not provided. We use DE, woodash, sand, and potting soil, mixed in equal amounts, in ours. For the first ten days or so no one would go near it. Then one day one of the older EE's jumped in and started to dust. Within five minutes they where all lining up to get in. It is very funny to watch them kick it around, shot some nice video of it this spring.