We received 5 chicks from MPC three weeks ago (barred rock, EE, leghorn, buff orp & a sussex; they are all different) and one of them (the EE) seems to be having an issue. We noticed she seemed drowsy and listless when they were about a week old. None of the others have ever picked on her or excluded her, but she seemed to be isolating herself - going to the other side of the brooder to nap while everyone else was busy eating and engaging in normal baby chick behavior. So we isolated her in a box inside the brooder, a little closer to the heat lamp since she's so small and cold. We treated her for coccidiosis, gave her a daily vitamin drop, and gave her crumble food (instead of a milled whole grain, which is local organic chick starter). She wasn't interested in the food, so we tried a lot of other things - food mixed with warm water, yogurt, scrambled egg yolk, other tasty and delicious treats. Still, no interest in food. So we started force feeding her by hand using the methods we found in the BYC forums. We mixed scrambled yolks, crumble, warm water, heavy cream, and various other calorie-dense foods. She gained a little weight, and seemed a more spritely. After 5 or 6 days in isolation and being hand-fed a few times a day, she seemed a lot more lively and lonely for her sisters. She spent a lot of time trying to flap out of the box. She grew wing feathers, but no other feathers. Since she seemed healthy, we allowed her to re-join the flock. Now they are 3 weeks old. While her sisters all weigh in over 5 oz, she is barely at 3 oz. We stopped hand-feeding her ("whatever happens, happens."). Her interest in food and treats waxes and wanes on a daily basis. If there are exciting treats in the brooder, she tries to compete for them, but since she's so small she is not very successful. If we isolate her with the same treats, she just cries to go back with her flock. We're at the point where we don't know what else to do. Do I want a chicken I have to feed three or five times a day? Is she going to grow out of it? Is there a chicken version of those genetic stunted growth diseases that some people have? What are the chances that we accidentally received a sleepy bantam? Etc. Any advice or reassurance? thanks in advance for reading & responding!