Peppermint Shrimp on an empty shell

The Peppermint Shrimp are great at keeping the Aptasia, or glass anemone, trimmed back. Since I added three of these guys, I haven’t seen any more Aptaisia. They also eat algae. Two of them will frequently come out during feeding time, and try to catch the frozen Mysid Shrimp I feed to the fish. I haven’t seen three at a time for a long time, so I wonder if one of them died…