To answer your question depending on what temp you are keeping him and they day/night cycle he may be trying to go off feeding. He also could just be going off food because he feels like it. Last he could be about to shed. My female went off food for three weeks just because she felt like it. Now she eats better than ever, but my male has just refused his first meal since I got him for his own reasons.
It is usually nothing to worry about as long as they stay healthy and are not noticeably thin.
My suggestions are: A) Keep him at normal temperatures. B) Only try and feed on normal schedules (not everyday...that may put them off the idea of food) C) Keep trying in a small container to reduce distractions. D) If he still hasn't eaten after three weeks you can try more elaborate measures (braining, scenting, smaller food, or a combination of all three).
If you need elaboration just search some care sheets online or post again.
Just get used to him keeping you on your toes when it comes to feeding.
Good luck!
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Thomas M. Marcy
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Madison, AL
Computer Scientist
Hognose Enthusiast