I sold ten excess chicks that I had. Five have since died. Absolutely no idea on either side what is going wrong. Please help! HERE ARE SOME FACTS: - All chicks have been on medicated feed. - All chicks have known how to access food and water. - Brooder temperature has been great. THE BACKGROUND: I had ten excess chicks that I advertised over CL for sale. All chicks were hatched in my own home from the same breeder: three two-week-old bantams and seven five-day-old bantams. They integrated well and all took a liking to each other right away almost immediately (which was a pleasant surprise). The runt of the bunch had a difficult hatch. Wrong end, and after waiting maybe a little too long, I ended up assisting it. It took an especially long time to strengthen the chick to the point where I could let it run around with the others. Runty chick got lots of TLC and supplements and made a seemingly strong recovery over the next few days. Shortly before delivering the chicks to excited buyer (day or so), runty chick dies. The previous morning, I had noticed it sleeping alone at the edge of the brooder. I thought this was odd. That evening, it seemed lethargic. Seemed to move in a dragging fashion and wouldn't take to water or food. I immediately isolated the chick. I also moved all chicks to an unused, brand new tote that I converted quickly into a brooder. For the sick chick, I administered Sav-A-Chick supplemented water by Q-tip (which it drank) and also antibiotics via Q-tip, which it took. I was able to feed it a little bit of egg and plain greek yogurt... The chick seemed to perk up slightly, even chirp, but still lethargic... Then it declined again, quickly, and passed away. I was stunned. It all happened in less than a day... Droppings appeared normal. Mouth appeared normal. Eyes appeared normal... I couldn't find any sign of illness! Alarmed and confused, I then supplemented the water for the chicks in the new brooder, keeping a close eye on them. I immediately contacted the buyer, told her what had happened. Suggested hanging onto them a bit longer to be sure. Buyer still wanted the chicks and has experience with them. I think we both chalked it up to "failure to thrive". So when the time came, I gathered up the remaining chicks and brought them to their new owner. It has been four days since... And four chicks have died. One is doing poorly. The remaining five seem just fine... but as the buyer said... it's like BAM... and they're dead. Literally, overnight. They are still on medicated feed. Still on supplemented water. Still under good temperature. Buyer says, "I don't have a clue as to what's going on with them. They all have been perfectly fine, then when I go to check on them the next time, (morning or night), then I find them dead. No apparent reason." Based on our conversation, buyer seems to have much more experience with chickens than I do. And has moved them inside to keep a closer eye on them. Please, please help! =( I am very upset about these chicks and worried about the chicks I currently have in the same brooder who are doing seemingly wonderfully.