They are active they love running and eating and their snack is always hard and they eat normally and they are currently on corid 10ml per gallon 6 weeksThat appears to be some bloody mucus from the intestines. How old are the chicks, and how are they acting? I might be tempted to go to your feed store and buy some Corid liquid or powder. If any seem lethargic, or hunched, and not eating, then ai would start some Corid in the water. Dosage is 2 tsp of the liquid, or 1.5 tsp of the powder per gallon of water for 5-7 days.