what do hermit crabs eat anyway?

so my parents return home today from a visit to the coast. my mom brought home a new pet for kid 1. its a hermit crab she found at the beach. okay, she's bringing a hermit crab. do she have something to keep it in i ask. well she brought it home in a cup but was looking for a cage for it at her house b4 she came over. she shows up with the crab in a large upside down plastic sheet cake plate. what?! how am i going to keep the cats away from it? she gives me a thin black plastic lid. okay, it needs air to breathe. she punches holes in the lid. i have no where to put it. she puts it on my kitchen table. what am i going to feed it? thats your problem she says. ?!!!
okay, so i have a hermit crab living in a cake plate on my table. i can hear its shelf scratching against the side of the plastic as it moves around. what am i going to do with this? i used to have one when i was little but for the life of me i cant remember what i fed it. for some reason i think i gave it fish food. i remember having a jar of something i bought at the pet store. so i am going to have to squeeze in a trip to the store tomorrow. hopefully sooner rather than later b/c i would hate to be responsible for this things death. well, it is kid 1's newest pet now. is she attatched to it? will she concider me a killer if i let it die? she's buying the food with her b-day money! i ceratinly dont plan to. and now it needs a suitable cage 'cuz this is not working. oh well i need to get more food for charlie tomorrow anyway. we bought him 12 crickets and he is down to 3 already. appartently my parents brought home a new cat toy complete with a new liter box. my cats think so anyway. this ckae sheet plate is filled with beach sand for the crab to crawl around in. she also brouht a bottle of sea water for it too. maybe i can pawn this one off on kid 1's science teacher. somehow i doubt it. i dont mean to be ungrateful to my mom for my kids b-day present but come on.
i took kid 2 to a halloween party today. we had a blast she went as a cowgirl. i braided her hair in 2 braids and painted some red freckles on her checks. she wore a cotton shirt and decorated jeans on top of red cowgirl boots. she topped it off with a purple cowgirl hat. she was adorable. the other mom's said so too. i threw that costume together in about 5 minutes this am, yeah. oh, and she brought along her toy horse head on a stick as her ride. very cute.
my cat is going wild right now. she cant decide which one is cooler.. the lizard or the crab. in any case she thinks i'm pretty cool right now. lots of cat toys.