Quote Originally Posted by Vasiliki View Post
The weight you get from 3-4 mice and 2 rats is going to be different because there is more 'stuff' in rats. With 3-4 mice, you have 3-4 sets of skeletons to digest, and more fur. With 2 rats, you get a higher density of food rather than more bones and fur.

I don't think it would be enough to really cause problems, but if you're asking the difference, there you go.
I am not buying any of this. First, bones are food. The snake gets a lot out of the bones. I am not convinced that the total mass of fur is greater in mice vs the equivalent mass of rats. Even if I was I have yet to see any evidence, let alone conclusive evidence that a Ball Python will be healthier on one or the other. I think that the health of the prey animals is a much bigger consideration i.e. fat vs lean rat or mouse.