Is he on mice or does he need gerbils? I'll never forget my first. I rescued him from a pet store that had him full of ticks. He was wild caught and never ate a mouse before. We had to give him gerbils until we could eventually get him to eat mice. We kept gerbils for their scent. We literally did a shake and bake with the thawed mouse in a bag of gerbil bedding.
After all that, we gave him to a friend who still has him.
Wonderful animals.