Mysterious worms?

OK.  The other night I was checking out my LR for signs of nocturnal activity (I have lots of "pods" and a few bristleworms) when I noticed what looked like two long round worms (not like the bristles) poking around about an inch out of some holes in the LR.  They retreated into their hole when I spotted them with the flashlight.  Then the next night Ichecked out the lair of my big fat bristleworm (the <<expletive>> killed my freaking sea slug!) and saw something very different in the large hole.  It disappeared really fast so I didn't get a great look, but it looked like a larger round worm or something (again, not a bristleworm).  I'm going to get a red filter for my flashlight so I can get a better look at night, and maybe even a pic or two.  Anyone everhad other strange worms in their tanks?  if by chance I have a eunicid worm or lysaretid worm(s) I want to nuke them cause there ain't no place in my tank for fish killers!  What are some good ways to get rid of them?  One of the rocks has lots of other good stuff on it (like bivalves, spaghetti worms, hammer coral, lots of pods, and even a tiny sponge).

Sorry for the long post.