How often are you feeding? Did he seem interested in the fuzzy or did he just ignore it completely? Usually young colubrids are little garbage disposals that eat until they explode, but every once in awhile they get picky or decide they're full. My corns have never missed a meal, shed cycle or no shed cycle, and my king only refused a couple times when I first got him and he was still a little nervous. One of my corns does prefer warmer, drier mice though. She'll eat it if it's wet, but she kind of pokes at it with her nose for awhile beforehand, whereas if it's nice and dry she eats it really fast. So sometimes they develop their own silly food preferences. I wouldn't worry about it unless he keeps refusing multiple times, and then you might want to start checking for some sort of illness/husbandry issue.