Hi! I have a 3 week old chick (his/her name is The Colonel), hatched by a first time mommy hen. He's one of 7 chicks. He had pasty butt the first week and I got him through that, he has been with his mom and siblings since. My problem is, he doesn't grow. He's a third of the size of his hatchmates. I thought maybe he was just really slow growing. This morning I had 3 chicks hatch in my DIY incubator. I fetched the Colonel and put him with the new hatchlings, to teach them how to chicken. I now see that he hasn't grown at all! I've attached a photo, The Colonel is the one I circled in blue, as you can see he is the same size or smaller than the day olds. He has been getting plenty of food, he's every bit as active and tenacious as his siblings. I'm a first time chick raiser, so this is a mystery to me! Anyone that can clue me in as to why he isn't growing, please?