Clicking sound

[Giovanni]

Are mantis shrimp the only ones who make this clicking sound? I have a cleaner but have never seen a mantis.

 

[XeniaMania]

Chances are it's a hitch-hiked Pistol Shrimp. I guess one way to tell is how many clicks you hear at a time. It's a pistol if it's sets of 2, and mantis if more. I caught the pistol shrimp in my system, it was only 1/2" long.