I did not have too much problems switching my bp's over, however, my oldest bp will not eat rats now, she ate them for 3 months, now she wants nothing to do with them, had to go back to multiple mice after she would not eat for a month. Once I gave her mice again, she is now eating just fine. My 2nd bp, Joe, pounds rats, no problem. And the baby of that group, he will eat rat pups very easily.