Little red mantis

[baussie]

About 2 weeks ago I acquired a little red mantis shrimp from my lfs. The mantis came in with a shipment of live rock, and after an unsuccessful attempt to sell the mantis, the store offered the mantis free to a good home. I found a piece of lr at the lfs that apparently is the perfect mantis cave (the lr does look like a cave with twists and turns, ledges and portholes..all which the mantis uses), because the little mantis took to it immediately. I suppose the mantis is doing a little interior decorating because I hear clicking noices now.
My first question is this...its color was more vibrant and opaque; its color now is now translucent. Is this a sign the mantis is getting ready to molt?
I'm feeding krill & brine shrimp...both are taken with great gusto.
What other foods should I offer to the mantis?

I can't believe that out of all the males in my local saltwater/reef club, the only taker was me, a female. Aren't mantis supposed to be manly critters?