Gorgeous snake there!!
He actually looks surprisingly well, given the time that he has not eaten for you. Even so, he needs to be getting fed as soon as possible.
How are you thawing out your mice? Is the mouse warm, if you thawed it in hot water, when you give it to the snake? Like Doug had mentioned, sometimes some snakes prefer the food to be warm, as if it was alive.
Also, do you have access to corn snake skins?? Perhaps the boa skin does not an appealing scent to it?? Whenever I would have a picky hatchling cal king refuse to eat after it was born ( I was lucky to only have this problem happen maybe twice at the most ), I had gotten them to eat pinks, rubbed and scented with corn snake skin. I would feed them one scented, and then throw in another pinky but un-scented. After doing that once or twice, the cal king was switched over to un-scented from that point on.
Have you also tried to feed the snake a mouse from forceps or tongs, wiggling the prey in front of it? Some snakes prefer that as well.
Is the snake being watched as the food is placed in his cage? Some prefer to be totally alone in the room, lights off and all, to eat in solitude.
Just some ideas. Keep us posted, and good luck!!
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Genesis 1:1