I am extremely new to chickens...and learning as I go. I have no idea how old our chicks are. How old are they typically when the feed stores get them? We've had them since Easter (1-1/2) weeks. Any input would be appreciated. Also...they are picking at each other something terrible....I've tried a number of things to get them to stop as suggested in other posts but nothing is working....I finally had to take the black araucanas out which seemed to be the aggressive ones. Suggestions?