I have 15 chicks that are 5 weeks old. One died last night of what i believe is an impacted crop. As I was putting them in the coop this evening I noticed another one has a large crop also. I am concerned that this one will die also. She is still eating and drinking and is very active. What am I doing that is causing this? Is there a special grit for chicks? or are they to young for grit? What can i do to prevent this from happening. I have been raising (hens) for 3 years and have never had this problem before. They have a pen that is attached to the coop and are outside during the day. I also have 11 adullt hens that share the same coop. They all seem to get along quite well.