I am going to assume you got your snake four months ago as a baby. Having said that, it would be ideal for you to go up to rats that are larger. I realize you have 40 mice so there are a couple of suggestions I could make. First, you could continue to feed the two larger mice until they are gone. I have never had any regurgitation or interruptions in feeding schedules. Seccond, you could always get another snake to eat the 40 mice .

Now, concerning switching to rats. I have never had a problem doing this. My snakes will eat anything. However, I have heard that this is not always the case. The best thing you could do is try. If it does not work you will have to get some information on how to make the transition with a reluctant eater. As I previously stated, I do not have any experience with a snake that will not take the plunge.

Jimmy