I have just started my flock. I have three golden comets and three RIR's. They all are about four months old and beginning to grow their tail feathers. When should I start feeding them calcium and grit? They are still eating crumbles. The Feed store where I purchased them had began to feed them pellets, however, I stayed with the crumbles. I have also introduced them to worms and insects which they love. I had some weeds and plants (nothing special) growing in their run , they have demolished them.