Well don't worry about them not eating for a while as long as they are not loosing weight dramatically.. My BP went about 10 months before eating.. I'm not sure if this is accurate advice but I'm sure if you want your BP on rats then you should stop offering mice.. It sounds like he refuses a rat so you just give him a mouse? When my BP went off feed I never once thought of trying him with a mouse I just offered different sizes rats every 2 weeks and one day he eventually took it.
How is your husbandry and set up? Maybe you could post a pic?
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