Help get boa eating rats

[Bogertophis]

Well, some snakes do have personal preferences. Rats & mice smell vastly different (I've raised both for decades) so presumably they taste different as
well. While it's unusual for a boa to be a picky eater, perhaps you have that one out of a hundred? (& I'm just making up that statistic as an example)
It may not be convenient for us but I suppose snakes are entitled to have an opinion, lol...

BTW, when I kept a large BCI for many years, she lived in a very large aquarium too, ate voraciously & remained healthy. I did as I suggested above- I
insulated the tank, & ran 11" wide UTH (Flexwatt) under 2/3 of her cage, & over that heated area I built a custom hide out of wood (coated with non-
VOC waterproofing) with a tile-board top & 2 doorways cut at the one end so she could enter & leave easily, & sure enough, she seemed to love the ease
of movement it gave her. It was about 5" tall, and even with 2 doors at one end, it was long enough that she felt safe & well-hidden.

But the best part of that was the rubber-backed (non-slip) carpet mat I put on top...snakes don't like to slip & many hides (plastic etc) are slippery on top
so that space is wasted. Not this one...I made the hide to just barely fit inside the aquarium, and she used the top (carpeted area) as much as she did the
"cave" beneath. Over that hide I used a warming light for her basking pleasure...in this way she had a choice of belly-heat & over-head heat. Don't let
anyone tell you that UTH doesn't raise the temperature inside a cage: of course it does...heat rises! But the amount of heat your cage retains depends
on whether or not you insulate that cage, & while UTH alone may not be enough (depending on your ambient house or room temperatures), it still helps
make their warm hide super comfortable & helps their digestion. Remember that heat rises, so while overhead lights (or CHE etc) do raise the cage
temperatures, much of their output never goes into the cage...it goes up & away, inefficiently. Be sure you are measuring the temperatures where the
snake actually is...I'm wondering if the cage floor isn't as warm as you've been thinking it is?

The better your snake digests, the hungrier they get & usually, the less picky they are about food... So I cannot guarantee yours will get on rats, but
he may if his cage is better regulated for privacy & warmth. BTW, my BCI's water bowl was on the unheated "third" of her cage, and she sometimes laid
there as well...they need to have temperature choices, & she never turned down food. Her tank was insulated- first I put up scenery on the glass (for me,
snakes don't care) and taped snugly behind the scenery are sheets of bubble-plastic. (you can also use corrugated cardboard, styro-foam sheets, poster
boards -w/ foam sandwiched between thick paper outside-, carpet tiles, cork, etc etc.)