MedUs_0oanswered grow question 5 years ago genetics, each living being differs from the others by different genes, I will give you an example of 2 dogs, born from the same mother, taken the same milk, etc. etc. and despite this one is bigger and the other is smaller, only twins make an exception, which I believe have the same genes. so don't worry it's normal. I hope I was helpful. sorry for the somewhat trivial example. I hope I have been of help. have a good time.