MIne eat anyhting I put in the tank, just like the bi color blenny. The neons are sure some fearless little fishes. At feeding time its akin to having a miniature mako shark in the tank....I just love the way it will grab a chunk of shrimp or clam etc and start the vigorous head shaking trying to tear out chunks like a shark does...Mine is always on a fish like a remora, but what it sees is beyond me, as I never have seen anyhting as a parasite or have my fish show signs of parasites...but what I ave read is they clean other fish like cleaner shrimp do, so I guess parasites is a biggie for it for snacks.