To be honest i have never fed any of my snakes including my BCI anything less than an adult mice, even when my BCI was a month old. I feed live and its not allowed where i live to sell mice or rats if they are not weaned. So when my BCI was a month or two old, i used to buy for him the smallest adult mouce that i could find. I,m not contradicting what you are saying, just sharing a different experience