My chickens have seemed to have stopped eating their feed. I have not changed the brand, I get them a layer feed. I did change from crumbles to pellets, could that be a factor as to why they stopped eating it? Have not had to fill their feeders in a week. The weather has been warming up and they venture into their run more, so I was thinking that with them foraging for bugs and what not that they don't need their feed as much. They do get scratch as a treat a few times a week. When should I become concerned?