Purchased twenty five chicks from a hatchery. All were healthy and grew well. Purchased another thirty chicks. One died in transport. Next day I found two chicks dead. My chicks have been dying one or two a day for the last nine days. Same exact environment, same food...same everything, except.... There was one Cochin chick from the first batch that I left in with the second. Two weeks older than the second batch. The first batch went into a larger brooder and are doing fine. The older chick in with the second batch was found dead yesterday. What is causing my chicks to die? I have raised a lot of chicks and have never had this problem. I am stumped! Need help figuring out how to save my remaining second batch and hope that it is not contiguous.