I have an assortment of 9 chicks that are about three weeks old now that I am keeping in the back room. The other night I noticed that the room smelled different, I'm not sure how to describe it. It was the smell of chicks, but it was sweet and rotten smelling. I seperated each chick long enough for them to poo, and only one of them is creating the poo that smells rotten/sweet. When I smell the chick itself, it smelled strongly of this different odor, more so than the poo itself, and most of the smell seems to be coming from its head. It is one of three polish chicks, and I thought at first it might be breed related, but the other two don't have the strange smell. It eats and drinks what the others are drinking, and is just as active and healthy seeming as the others. It didn't used to smell like this. I thought maybe there was something wrong with its dome, but I couldn't find anything, and I'm not sure I would know what to look for in the first place. Has anyone experienced this in chicks before?