The tank has been up for 4 weeks.  This worm just appeared out out from under a rock one day.  He is without a doubt a hunter.  I have seen him snag and try to eat a hermit crab.  Whenever the tank is fed, he pops out and looks for food. (yes, with the lights on)  The strange thing is that we pay very close attention to the tank, and this guy who I estimate to be at least 3-4 inches long and about as big around as a pencil has managed to stay hidden.  We think he is a fire worm, but any help with positive ID would be appreciated. I think he needs to go?  Any suggestions are welcome.  Email Jody@fullauto.org   Thanks for looking.