Hey guys. I'm in a really frustrating situation here and just don't know what to do. I've been reading dozens of these forums for days and just can't figure out what is going on. So here's the situation. I got four couple day old bantam Cochin chicks from a reputable breeder in my area. They got all set up in my brooder and a few days later I put a couple of chicks one of my hens (a mean broody, always tries to kill her chicks) hatched in with them. After a couple days the Cochins started doing the gasping for air thing and looked really weak. They started to die off one by one until all four were gone. But my other chicks are still fine. The breeder kindly replaced the chicks (from her seemingly perfectly healthy flock) with four new ones who I set up in a whole new completed fresh and clean brooder all by themselves. Well tonight, without any gasping or other symptoms, two just dropped dead. I fear the other two will be gone by morning and I am just so frustrated and distraught and confused. What is going on here??? Any ideas? I'm at a total loss. Thanks so much for any insight, I really need it.