I can't give you too much advice from an experience point of view. We had to assist feed my enchi lesser two or three times before she would take live. I'm not sure if it helped or not but the last time I assist fed a F/T mouse pinkie I cut the skin on the head to get it bleeding a bit before we assist feeded. This may have given her a better taste for the mouse I really do not know. I have heard that switching to rats or ASFs can help occassionally. You can also try leaving the F/T in the cage with them but be sure to not leave it in all night, we did once and will never do it again, stunk really bad.