I think everyone misunderstood just a little. I didn't mean to present this as a scientific study or hard evidence to the fact that rats are better than mice for feeding ball pythons or any other snake. I just thought it was very interesting that my balls were growing at approximately the same rate, and that that rate was much slower than that of my roommates' who were also growing at about the same rate as each other, but much faster than mine. I know this is no guarantee of genetics or anything, but the two CH girls were purchased from the same breeder at the same time and were approximately the same size at the beginning. Initially pumpkin (my CH girl) grew much faster. This was during the time period when we first got them and they were our only balls and they were both feeding on mice. Once my roomie switched to rats, however, Pecan quickly surpassed pumpkin in both growth rate and weight. This was the same case with my pastel male and her pastel female. They were both purchased from the same breeder at the same time. She started out much slower, but quickly caught up once she had a few weeks on rat pups. I know snakes can grow at different rates from one another, but I find it strange that ALL of her snakes would have hit their growth spurts while NONE of mine have. Being that there are so many experienced keepers on this board, I was only looking for some opinions on why this might be, and trying to present the facts as they happened/ as we recorded them. It will be interesting though. If I ever get to the point where I am breeding a few clutches a year, I might try randomly assigning them to groups and feeding them different things once they get established. That will be a long time from now though. For the moment I will be keeping mine on rat pups, just to see if they continue to grow at an accelerated rate. Thanks for the posts everyone, you have all pointed out some factors we hadn't thought about!