Mine never bothered a thing until it got to be 10 or 12 inches. It was like all of the sudden my food wasn't good enough. I think a lot of the temperment of these things just varies from star to star.
That's awesome if you've found one that's content to scavenge. My sand bed has never been as clean as it was when I had my green brittle.
To answer the original question though it helps to spot feed these things to curb their appetite. I fed mine silversides and cocktail shrimp. Man as soon as either one hit the water the green monster would come out of no where on a mission.