Comparing size based on a cropped picture with not much for scale is near impossible IMO
1 don't use a bright light, use the dark red or black if you have no option but to use the tank.
2 take actually temperatures ON the bottom. Thermometers on the glass are not an accurate reading of where the snake lives. With a light for heat it is hard to get a long gradient heat pattern. 78ish to 85ish might be a good range.
3 As stated house alone, in smaller housing is better, but if using a 10 gallon and a feeding issue use a lot of hides, small and of various types. Even a piece of cardboard over aspen bedding.
On to feeding
Feed in a container, small with air holes. like a deli cup. They should not be able to see out to see people moving around.
I like to place it in the middle of the cage, and allow them to try to eat over night.
Personally I like small paper bags. If you watch a baby snake in a deli cup they at time just rub around and around. Just a presumption, I think the corners help in a bag? but the idea is to get the snake to be near the food at all times.
Feed options
Live pinky
frozen thawed
frozen thawed brained, a hole or cut into the head to help with scenting.
frozen thawed warm to the touch, NOT hot, but heat the snake can detect.
Wash a pinky in a mild soap such as ivory then thoroughly rinsed and dried.
Scenting a pinky
this list is long. And I hope you don't get to this point.
other rodents (bedding can be used.)
tuna
lizards
many many more
Good luck
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Thanks for reading.
Big Tom
www.HerpZillA.com