I finally found the old post where we were discussing killing these guys. So, I should not be using freshwater but REALLY high salinity water? Are we talking about dipping the rock or letting it sit in there for a while, overnight? Will the mantis skitter out or die in the hole? I want to be sure that I do not let him back into my tank alive. I think that he is sitting in the rock in freshwater munching on my Bicolor right now :cry: