My little Silkies are various ages, the oldest one is about 12 to 14 weeks old and the others are little chicks still...maybe about 6-8 weeks old. I have fed them a commercial starter grower feed since I got them, but yesterday I put them inside a large fence enclosure to peck around in the grass and flower gardens and they were eating quite a bit of 'stuff', so I got some sand and put some clumps of it on the ground - it was damp from the rain, and they started eating it like they were starving. They must have really needed it.