Thanks for the info on stirring the litter. We have had a few warmer days in MI and we decided to do a total removal of litter, as for the chicken in house she is now back with her family and we are excited to report all are happy and healthy. It was the ammonia level being to high and burning her eyes. Antibiotics were not needed for any chickens. What I have learned is ventilation is a must and its a fine balancing act between keeping them warm in Mi winters and keeping quality air in your coop for the chickens to breath. Its always tricky this time of the year in MI as it can still be cold here for the months of March and April. Removing the well developed litter to soon could really hurt the chickens as far a heat that the turned litter is giving them. As far as knowing not to treat with antibiotics that was easy, with in 4 hours of the removing Marg from the coop, the foamy eyes disappeared.