Yes, it is best to make him feel safe, content and secure in a smaller (instinctually "cave-like"
cage or sweater box with low light or extended "night time" periods. In addition to this great advice this guy gave you I would suggest that you try using pre-wean rat pups and leave them in the cage overnight. Pre-wean rat pups will not pose a threat to the snake and will offer movement that the snake may be more apt to go after. If he doesn't eat it by the next day the rat pup should still be fine and can be returned to a rat mother. Since this snake is only 3 feet this should offer an adequate meal for him, especially considering that he has gone so long without food. If this works and if and when he grows you can also do this technique using rabbit pinks (or "kits"
. Again, it poses no threat to the snake and offers him more appealing live food to kill and consume.
I hope this helps
>>First off, a 3' snake in a large vivarium with no hides??? Have I mis-understood?? A 3' acclimatising retic is better off in a much smaller enclosure, or tupperware box. Keep it warm, dark, and give it access t a damp box. Then, when the lights out put a warm small rat, and a warm chick in the enclosure and just leave it be, see what happens.
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"If I had 365 enemies it would only take a year out of my life to settle all scores." Mia Miselfani