So, my baby chicks are 3 weeks old now. They eat their chick starter. On occasion, for my personal entertainment, I toss a few frozen blueberries in to watch them chase each other around. And the kids will toss in a rare cricket or other bug. (maybe one or two a day.) I've been told that the chick starter should have enough grit to cover their needs. Is this the case, or when we start tossing in things like bugs and blueberries, do we need to add some grit?