I had one two inch mantis and a smaller one with my liverock.com order. These were caught before I put the rock in the tank - as they were in the water at the bottom of the bag. I have started hearing a new popping noise after 6 weeks so I will be on the lookout for another. Just a fact of life with live rock.
55 gal. reef. Coralife lunar lights 4 x 65, 120 lbs live rock. Remora skimmer, 3 power heads. 2 tank raise false percula,2 pajama cardinal,hermits, snails, Xenia, leathers, mushrooms, polyp frags, yellow sea cucumber, And last but not least - the miserable mantis.