Got em!
He just wandered into the trap out of the blue while I was checking out the tank. There wasn't even any food in it. He's in the quarantine tank now.
I'm doing a little experiment to see if polyp extension and color improves in some of my Acros, particularly my milliporas. I have a couple millis that have had practically zero PE and growth for well over a year. I have never seen the CBA bother anything and have great growth with most of my corals, however, several folks on the SPS board suggested that the angel may be the cause of the poor PE and growth and that just a few unnoticed nips a day could be to blame. A few months ago, as a test, I placed a frag of one of the millis in my frag tank; PE, color and growth improved dramatically in a matter of weeks. I'm now removing the CBA to see if I get the same result in my main tank or if the improvements were do to differences in lighting and/or flow in my frag tank. I figure I'll notice something in about 3 weeks.