My 3 yr old RIR has been acting strangely lately. She hasn't laid an egg in over a year, but for the last two days has been spending day and night in the nest box. She did come down, however, when I let the girls out for "playtime". She didn't seem interested in eating any treats or even scracthing around the yard. She simply stood in one place. Yesterday I picked her up and her crop was "bubbly" and full of liquid. When I touched it, she threw up a brown liquid. After reading about sour crop on BYC, I turned her upside down and "induced vomiting". What came up was dark brown mush and two whole grubs. She was very tired after the vomiting, but a four or five hours later stood up and drank some water. The only poop to come out has been small dribbles of a yellow liquid. I have read to give her olive oil soaked bread (which she will not eat) and plain yogurt. Does anyone have any advice on how to get her to eat the yogurt? Does this sound like sour crop? Today her crop is again full of liquid (not as much), but she is much more lively. She protested a bit when I was masaging her crop. There are no hard or lumpy spots in her crop, nor do I feel any grit in there. Do you think I should inducing vomiting again? Some sites suggest that this could be VERY harmful to the hen and that the stress of the experience could kill her, and should therefore only be done once. Also, many have suggested obtaining apple cider vinegar (for horses). As I live in a very urban area, I have no idea where I would get that! Any advice would be greatly appreciated. Thanks!