I would also consider treating them for coccidiosis, since the symptoms are hunching or standing puffed up with neck pulled in, lethargy, runny poops with or without blood, poor appetite, and ruffled feathers. Sometimes they will also have a slow emptying crop with cocci. Treatment is Corid or amprollium for 5 days. Watch others for those symptoms. Make sure that your ventilation is very good, and keep the litter clean and dry to prevent respiratory diseases. Using a probiotic in the water twice a week will help prevent diseases.
I noticed one of the others sneezing so I went out first thing this morning and got them some antibiotics......hopefully it gets rid of whatever they have.
