I had a hen lay some chicks. I took them away from her because the cat was killing them one by one. I raised them from a couple days old and now they have been changing colors. She is a Nanking and I have a Rhode Island Rooster. I figured they would have a mixture of the two. I looked up the breeds on the Backyard Chickens and found out that I have 2 Plymouth Rock hens, two that look like RIR, a Nanking roo and a gray colored one. I don't want to sound uneducated when I ask...how does this happen? I know it couldn't be mis-breeding. We live on a dead end road and there are no other roosters. Thank you to anyone that can clear this up for me.