They weren't supposed to be. How do breeders create a bantam variety of a large breed fowl? Do they just choose the smallest or do they cross breed with a bantam?
A few months ago, I bought a trio of blue laced red Wyandottes and of course one of the hens turned out to be a rooster. The extra rooster is bantam sized, the other rooster and hen are normal sized. They were raised together and fed the same. Is this a normal occurance?