did you do the ratty dance? using forceps you grab the rat behind its front legs and simulate a live prey for the snake to be fooled by.
another method is scenting enclosure before introducing prey item. some rat or mouse bedding in the tank to get your python in feed mode so once the rat is introduced the snake will go for it.
another method of coaxing your snake to accepting thawed rodents is to prekill so its more fresh smelling to the snake
someone will offer better more hands on advice since i feed live
0.3 wild type ball
0.1 spider ball
1.0 bumblebee (spider x pastel)
I heat my prekilled(when they have cooled down) a little in a tupperware tub and a blow dryer. I don't cook em just give a little heat signature. Works for me.
I put the mouse in a plastic bag and in a ziploc bowl with the lid on in hot water for about 25 minutes and then just stick it under the heat lamp for about 30 seconds and he seemed to enjoy his first meal. I hope this helps...
Since you say "thawed" mouse but don't talk about warming it up, my first guess is you didn't have it warm enough. A mouse's normal body temperature is a little bit higher than a human's.
I agree with Heather, we need more details about what you do to be able to give you better help.