It sounds to me like you are doing everything right EXCEPT:
1)need a slightly bigger enclosure to create a heat gradient.
2)you need to use eco-earth coco substrate or similar, misted occasionally to keep humidity up.
3)and last, but perhaps most important, you NEED to heat the thawed rodent up to 100 degrees with a hairdryer right before feeding! I found feeding thawed rats, and them being refused to be a huge pain and til I started using the hairdryer method.
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