I made the surprising (and admittedly unpleasant) discovery that fire urchins seem to be omnivores... when I discovered mine munching away at my lovely maroon feather duster. The worm did not survive the encounter. I've started to feed it bits of supermarket shrimp, and it always hunts down meaty scraps in the tank with a feverish and disturbing urgency. Does anyone have any advice on how often I should be feeding it meat?