Melanurus wrasse will pick at them until they get chipped away. Coris (yellow) will as well. But both of these fish will eat feather dusters too. I've had really, and I do mean REALLY good luck with a Melanurus wrasse. Especially the females. They seem to be hard working fish. My male has been more of a diva. I keep 2 in my macro algae seahorse tank where I have to feed very heavy, and they do not bother the seahorses and they have eliminated about 90% of all pests. Everything from flat worms, to vermetid snails, to bristle worms, to other creepy crawlies. They do not touch aptasia though. They also do not bother my cleaner shrimp, clam, or blood read shrimp. I'm constantly bringing in new pests too whenever I get new macro algae, there is always, always, always something and the mels are quick to scout out the new acquisitions and eliminate the problem. They've also proven to be save with all kinds of coral.