I feed her twice a week or so. Frozen foods are the best, and most healthy, option for Marty (great name btw). Frozen shrimp, squid, scallops, mysis, and silversides are all great choices. Scylla also likes the occassional octopus tentacle..lol. I do actually keep hermit crabs and a variety of snails with her. She eats some of them, but most of them just hang out around the tank. I would recommend adding some cleaners to see what happens. Mantis generally prefer snails to hermits, I think, but they do like true crabs a lot. Scylla will eat fish as well, but I think she just doesn't want to put the energy into catching the molly...too easy just to grab a snail or hermit. I'll PM you my number and my Yahoo Messenger ID, both of which are good ways to get in touch with me in the evenings and on weekends.