spionid

I’ve found a small number of these on the glass over the last couple months. They’re pretty rare in my tank. My guess is some kind of spionid, but I’m not sure if it is a problem yet. I know some of my hermit crabs have come in with (possibly boring?) spionids in their shells, but these were...

I know they aren't too harmful to things but I just don't want to have worms burrowing into any of my corals. And Im worried about the future of my tank. I have some spionid worms in my sand bed. Anyone have any luck with creatures / fish that eat these worms, Ways to control the population, or...