Best way to catch pesky critters? I believe i have a hitchiker i'm unaware of. I've had starfish begin missing parts of their arms. I had a crab with pointy black claws show up dead recently. I never saw him. And i believe i've heard clicking in my tank. But i've never seen a pistol or mantis. I need to find the culpret. I've had many fish die or disappear a few days into having them. I know that it could be from stress and such. But with the amount of fish i've had die, even with extra care during acclimation, there has to be something else.