It sounds like you're scaring him with it.. Don't touch him with it. Is it warmed up well? It must be completely thawed and then very warm to the touch. Then hold the tail with feeding tongs a couple inches in front of the snake and do the "zombie dance". Make the rat move slightly but not too much or it will scare the snake. If this doesn't work, try leaving it in there with the snake for a while. Only feed at night in a dimly lit room, and in its own enclosure.

It may still be unsettled about its new surroundings. What is your set up like? Enclosure, heat source, hides, temp and humidity, how are you measuring these things? There are many factors. Also, was it eating thawed rats when you got it and what size?