What is his weight? Depending on his weight and he can afford to lose a little I would stick with it. This is where the tough love comes in IMO. If he is refusing monitor his weight and if he loses to much then you may have to go with mice. You have gotten this far so there's no reason to turn back now. Make sure you don't leave him alone with a live rat, it only takes a second for something to happen and it's up to you to react quickly. Also make sure the room is dark, a red or blue light comes in handy to feed in the dark so you can see him but it's still dark for him. If you don't have a red or blue light then make the room as dark as possible with you still being able to see whats going on.

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