Beareef:

WELCOME to maast! Are you sure it's a mantis shrimp and not a pistol shrimp? They're the ones known for loud clicking. Anyhow, I'm sure there's someone in our organization that will take the mantis shrimp; lot's of people keep them. Just not in a mixed reef! There are plans for traps on some of the boards like reefcentral; basically they involve cutting a plastic soda bottle and inverting the "funnel" top so that it leads down into the rest of the bottle. Put food in, the shrimp goes after it, can't get out. You can buy traps too; they might be better.