I had a peacock and also took on my cousins hitchhiker who was a Gonodactylus childi.
With the smaller g.childi, take like a skewer with a small piece of shrimp at the end and see if it will come out and take it. or just drop in a small piece of shrimp by its den, it will likely find it.
He will also feed on your pods in the tank.
Just make sure your iodine levels are good for it to molt and look out for shell disease on him.
Here is a good site that I learnt a lot about mantis shrimp from,
http://www.ucmp.berkeley.edu/arthrop...html#directory
it's also a great place to find out exactly what species it is.
Roy studies stomatopods everyday, he's the guy who knows it all.