Hopefully they will all come along, sometimes it can be easy, sometimes tricky. But you seem to be seeing that. You can try the live rat pups, but sometimes a little patience doesn’t hurt, and double check your husbandry (no one’s perfect, I know I’m not) and soon enough they’ll all be eating. And I’m also guilty of using fresh kill to get a boy or two started myself. So if your gonna be feeding rats, why not? I’m a mouser that’s why I said it that way. Best of luck!