Apologies for the gross picture. 1-year old chicken who acts normal, eats & drinks & free ranges with 7 others. She seems very happy & alert and has acces to oyster shells and 5 acres to roam. Two weeks ago, I notice her messy bottom, cleaned it, and it was fine for a couple of days. At the same time, I started to find eggs with a long trailing sack. The end of the sack is about 1/4" thick and like a hard plastic. What should I do for her?