Your monitor's behavior is telling you something. Its your job to figure out what is up, not 'get' the monitor to do anything. They all like rodents, that is not the problem, the problem is figuring out what is amiss with your guy.
How old is yours? I had a tiny baby rudi that would not eat them for the first month or so, only crickets. So maybe age plays a part? I don't know for sure, because this is only one instance.
Other than that, most times, any refusal to eat food is related to husbandry issues. Security, hydration, adequate range of temps (not just heat, but cool too.) etc.
Is he eating anything at all? If he will eat supplemented crix, he will not starve. If your husbandry is good, you will soon wish he would refuse a meal once in a while.

D.