The chicks were all together. I moved them out of the brooder into a closed coop. I had another flock previously in that coop that had just started laying, so I shifted everyone around. I had cleaned the coop but obviously not well enuff. Because within 3 days I had a 6-week old acting lethargic and puffed up. I separated it fm the others. Within a couple hours I noticed a couple more acting funny. A total of 6 I pulled out. After the second one died I figured out what was going on and started corrid right away, on all of them --but the 3 and 4 baby was past the point of drinking anything. I tried using a dropper to get medicated water down them, but it was not enuff. By morning they had died. The last two have turned around completely. And appear to b no different then the rest of the population. Since they all were exposed, I treated the whole flock. I'm just wondering if the 2 that's we're separated can go back with the others now? All are still doing corrid for 4 more days...