I woke up in the middle of the night and was checking on the tank and my crocea clam had moved about a inch. For some reason, it released the clam rock it was on and just moved onto the direct rockwork. On the clam rock, the byssal threads were visible. I tried gently nudging it and it had already laid down new threads. Is this normal, particularly for the threads to be left attached when it moved, or is it in danger of having it's health affected. I've always heard that you don't want to tear their threads, but wasn't sure why it moved. There is no change in flow or light where it moved to, it just adjusted to a slightly different angle and closer to the rock since the clam rock was sitting slightly higher than where it moved to.