One of the girls was being a pest today while I was cleaning out the coop and as I was shoveling out the shavings she was digging through them---I thought she was looking for bits of pellets or grain----but NO--she was actually grabbing mouthfuls of shavings and swallowing them So I shooed her away, finished cleaning and put nice fresh shavings and stall-dri in the coop and she march right in and started in again grabbing the shavings and eating them. I haven't seen the others doing this. I am a bit worried about crop impaction They have layer pellets, oyster shell, grit, fresh water and get scratch grains, wheat bread and various fruits and veggies and they free range all day long. So what do you think might be the cause of this odd behavior??