Huh? No, feather dusters that come on live rock do not move.. heck, even the large feather dusters with soft tubes don't just "get up and move". They usually go through several stages to let you know they are not happy, then if you don't do anything about it, they normally die. This is just for large feather dusters, not small ones on live rock, first they will usually not open up much when first irritated... then they will lose their crown (feather top), and in rare cases, they will crawl out of their tube (since they are worms) and at that point will attempt to move.. but I have never heard from anyone of that happening in the hobby in all my years, just read it in books. Also, if the worm does leave the tube, they are preyed upon by other things in your tank, fish, crabs, snails, etc, and normally don't live long enough for build a new tube anyway from what I have read... but if it was so unhappy that it left the tube to begin with, chances are that it is not in a healthy state at that point.
