Very new at this whole chicken thing. We have one chick that is about half the size of all the others. Attached is a picture of it next to another chick the same age. We got 10, 1-day old chicks in the mail (8 1/2 weeks ago) and it's the only one that really isn't getting bigger. So, small it can squeeze through the whole in a chain link fence still. It's eating, drinking and pooping normally. Should we be worried or is it just a runt? Do chickens have runts (like in a liter of puppies)?