We have a Delaware hen who has suddenly developed a large swelling on the right front of her neck/upper breast. She is in a tractor with 4 hens of the same age. They are molting so between them they are only laying 1-2 eggs per day. We acquired the hens about a month ago from a small commercial flock (300 hens) that was going out of business. We were told the hens were about a year old. I thought it might be an impacted crop, but wouldn't that be more toward the center? They eat layer crumbles supplemented with pasture. It has been very hot the last few days but we've kept them supplied with water & shade (Western Washington, so not crazy hot). Any thoughts on what this may be and what we should do? Thanks!