Okay - so I'm a newbie chick mama. I have 9, two week old chicks (3 leghorns, 2 RIR, 2 Production Red, and 2 Ameracauna). I just moved them yesterday from the smaller indoor brooder, into a larger brooder in the garage. This evening I was cleaning up, feeding them, and rotating my "mama time", where I pick each one up for a short time. Well - my 3 leghorns all have this icky knot on the right side of the lower neck! The first one I picked up has it larger than the rest, and I thought maybe it was a deformity. But then I noticed that all 3 leghorns have it. It looks like a marble under the skin. Any ideas???? I have NO IDEA! Thanks!