I disagree. I think you can certainly get him to take f/t .......IF you go from rat pups to weanling rats. There is a pretty big size jump from rat pups to smalls.......he could be freaked out by the "huge" rat. Just make sure you thaw it out and it is warm enough, then wiggle it just a little. I have a pastel male who is close to 3ft, and could probably take a small rat, but he won't. But he'll take a f/t weanling like it's nobody's business.