Among my acquisitions at the Lansing Swap, I got an beautiful rock anemones and 4 peppermint shrimp from Dick Perrin at the Tropicorium booth. After be home and in tank for couple of weeks one of the peppermints started picking at the nem. At first thought it was just searching for food, but noticed that it kept coming back to the nem, I even moved the nem and it still found it. After nothing else worked to keep the peppermint away I moved the nem to an qt. I was too late and he didn't make it. Is this an common problem with peppermint shrimp or did I just get an rough one?