I was just getting ready to post help my chicken has a large lump I'm freaking out. This is one of my favorites I love them all but really love this one. Then I did a little research on this sight and found out its a crop where they store food. I'm so glad i did not run down to the neighbors who has raised chickens for years and ask this question. I'm sure they would have had a good laugh. So thanks again to such a great sight with so much info that helps us beginners.