Mantis or Pistol?

Tonight I just came to the realization that I might have a mantis or pistol shrimp lurking in my LR. I haven't been able to locate the source yet, but the "clicks" seem to be fairly frequent tonight. This isn't the first time I have heard it though I never thought much about it until I noticed it happening every few minutes or so tonight. I think I just assumed the clicks were snails in the past since it was rare that I heard them.

I have read a bit about them but I don't have any experience with either right now. I am guessing that if I do in fact have one of these, it is probably fairly small. While my snail population has declined quite a bit over the past few months, many of the hermits are sporting shiny new shells, so I chalk that up to them.

I just want to figure out if I should worry about it and start what could be a painful task of trying to outsmart it, or if I should just monitor for the time being.

My tank is a 75 gal with over 100 lbs of LR, flame angel, few chromis, couple of clowns, peppermint shrimp, emerald crabs, hermits, etc. I also have a handful of corals; star polyps, zoas, lobo, kenyas, and mushrooms.

 

That sounds like my experience so far. I haven't noticed it with the feedings, but after the lights went out, there was quite a bit more activity.

 

Do you think a pistol (the shrimp kind) would be fine to leave in a reef tank or are the generally destructive?