I have a mixed bag of chicks all different breeds...picked up from a local chicken lady. Bought 10 and 6 have died. Look fine one moment then I check again and 1 has died. The living are 3 weeks old now. The 4 living are sneezing and twiching, what should I do? They are on medicated chick feed, with fresh water, and litter. I just dont understand, what should I do? Are my other chickens going to get sick or my kids for touching them? Please help ASAP!!!!