I always give the birds every supplement separate that way they only take what they need and when. The red pick pots are a staple part of their requirements all year around. I believe the red stone has medicinal properties, similar to nature programmes when you see parrots eating clay etc. 2014 season I had my young birds back from a race and a silver hen dropped in, went straight to the red pick stone, not the drinker or feeder. She filled up on it. She was the only bird that DIDN'T come down with young bird sickness that year. Now that might be a coincidence, but that hen knew she needed red stone, over and above a drink. It just confirmed to me that they know what they need more than I can predict.