Ferret growth

Question
I adopted 2 ferrets from a local pet store last November. They are both female and I am assuming that they are about the same age, as they were the same size when I got them. "Spaz" (named for obvious reasons) seems to be growing, but her cage-mate "Bandit" (named before we knew she was a girl) isn't growing as quickly and is almost 1/2 the size of "Spaz". "Bandit" eats, plays, and does everything a ferret should do - everything black is HERS -- but her size worries me. I have tried different foods, and I do give her supplements, but she only likes a certain type of food. I was reading that ferrets can have high-quality cat food, like Iams. Is that true and do you think I should try seeing if Bandit would eat that for possibly more protein/better nutrition?

Answer
Ferret size is partially determined by gender, but also genetics and diet. Usually females are rather small, but I have seen some large ones. It's perfectly normal that one is smaller than the other, ferrets range from size just like people. As long as they are both eating, drinking, pooping, and playing normally, and seem happy, there is nothing to worry about. While ferrets can eat high quality cat food, ferret specific food is best. Or you can mix them, which is what a lot of people do to ensure that they are getting a balanced diet and in case one brand changes its formula or is discontinued.