I noticed one of my zoa appears to be melting. It closed up, shriveled and got really dark overnight. Looking closely it has small white bugs crawling all over it. The bugs appear to be eating the dying zoa. I now notice the bugs all over the tank. Are they attracted to the dying zoas... or did the bugs kill the zoa? I removed the frag and dipped it in revive, here is a pic of the bugs.