We bought some California white chicks and are so surprised how different they are then the rest of the chicks. 3 out of 4 at 5 weeks are huge (I mean they look almost like a full grown chicken) and 1 looks normal size compared to other chicks their age. The difference between the one that looks normal size to the other 3 is not double but possibly 4 times. They are so big that they cannot even walk far and walk a few steps and lay down. Is this normal? They do not have a more intense red crest or larger than the smaller California white. I don't know if these are roosters or they are genetically modified? I have other chicks that I clearly see the difference between pullets and cockerels. They are a little bigger but not anything like these whites. Thank you for your help!