What are you using for heat? How are you regulating it? And where are you measuring temps from?
How are you preparing your ft? The one meal she ate was that live or ft?
I am also thinking the ft might be a touch too cold. So she's either getting shocked when she bites it and its too cold or it cools down too fast and she's losing it.
Normally ft items should be heated to about 100.f. This is the normal temp or a live rat.
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