I used to have a mantis shrimp in my tank. His home was a huge piece of base rock. I tried a mantis trap, but the only thing that happened was the brittlestar would try and get the bait out, and his arm would get snapped off. We call him Stumpy now!
I tried taking the rock out and flushing it with regular tap water, then I squirted some liquid calcium in the holes and another flush with tap water. But the only thing that killed was all the life on the rock.
When (long ago) the dwarf angel came down with ich, I put this rock in the QT with him and treated the tank (no, not with copper but on the box it said "harmful to inverts".....too bad the mantis didn't read the box) and afterwards, he never looked better!
So after we moved, the large base rock was placed in the lionfish tank and one morning the mantis was surveying his home when the lionfish swooped down from behind! Poor little mantis! <img src="graemlins//uhuh.gif" border="0" alt="[U-Huh]" />
My advise? Get a lionfish! j/k!!!
BTW, mantis click too.....
I know I wasn't much help, but I will offer my cyber support and hope you rid yourself of this pest!!! Good luck!!