Mine only eats if he is in his hide and hasn't been moved/frightened by it.. First we make sure the mouse is hot enough(temp guns rock!) to match living temps, having the head be the warmest part. I also make sure that it isn't cool on the inside, it's warm all the way through. Next...Barely dangle it outside of the hide, watch for fast tongue flicking and for the snake to follow the rat..don't let it bonk the snake, that can scare him into not eating! Mine is afraid of the full on 'zombie dance', but with a little bit of wiggle/twitching he strikes quickly!
Another tip is feed smaller than your snake currently eats. More likely to grab it!
Eventually the snake gets used to the dead rat smell as being food, and that's why I warm our rats in the snake room. The warm air circulates the smell and it's like the poor snake has to wait for cookies to get out of the oven, and they are way more likely to gobble it up afterwards!