Cool, what are you going to do with them? My dad used to buy mantis egg cases to put in our garden. We never saw any in our yard, but they would be all over the rest of the neighborhood. I hatched one a few years ago and raised up a few, but I ended up feeding them off to my old chameleon.
Well they were originally for the greenhouse, but they are just to damn interesting, so we have some that hatched last month in an exo-terra thing. They are pretty interesting little creatures.