Are you feeding frozen thawed, live, freshly killed? My hognose ate frozen thawed fine for the first 3 feedings, then stopped eating. I tried putting her in a bag with one, exposing the brain and still she wouldn't eat. After not eating for a month, I gave her a live pinky. She gobbled it. Now all I feed her is live (2 pinkies at a time) and she has not ever given me a problem.
If you are feeding frozen I would try the bag etc first, but if that doesn't work try a live pinky. And of course this is all moot if you are already feeding live prey.