How is your husbandry? That is the first question with non eating little ones.

If everything checks out that includes AMBIENT temps that are at least as important as surface temps. ( the ambient temps should be 80-85 )

Is the enclosure in a quiet area. If everything temps and humidly wise are good and there is 2 hides of reasonable size I try to keep from touching or otherwise bothering the snake for 2 weeks and try again. Pre-scent the room (leave rats in there for 20 to 30 min before offering) so that the snake will warm up to the idea. Hopefully that will work.