My Ball Python is Hungry but Won't Eat.

Either the tank is small or the hide is to big for the snake. If that's the large exo terra rock hide and the snake fits in it snug the tank is to small. If the snake has alot of space in the hide, it is to big.

Out of all the cheap pet store gauges the one you have is one of the better ones. I have three and they are usually pretty close to my digital.

I think your hide is to big and your snake could use two snug ones. Four the time being you could use small boxes. Once it feels secure and the temps are right it will eat.

When I have a snake between sizes of hides I will put dry moss in it to make it seem smaller. But if the snake is swimming in it you should get proper sizes. These are cheap and easy to clean. http://www.reptilebasics.com/hide-boxes

What is the tank size?
What type and watt bulb are you using?

It really looks like your temps are a problem. You stated an 80-90deg range, but from what I can see, you only have one (not-so-great) thermometer. Does this mean the tank temp is swinging ten degrees? What is the temp directly under the light, and what is the cool side temp?

Stop taking her hide away when you try to feed her. BPs like to feel safe and ambush their prey, which they can't very well do if you make them feel exposed and in danger themselves right before dropping in a rodent. As long as the rat isn't hungry and dehydrated when you put it in the cage, it isn't a danger to your snake for only a short time period. If rats were immediately scared the moment a snake looked at them, then you wouldn't see them climb on them like little hills when exploring the cage.

I'm pretty sure the tank is a 30 gal fish tank and it's a 100 watt bulb, we had 75 watt but it did nothing. I suppose there is quite alot of room in her hide, I never noticed until you said that. I was planning on getting moss anyways for humidity reasons, but I'll buy a smaller one for the other side. Would there be enough room in there for her with the water in the middle too? (She's about 4ft)

Can you get moss at a pet store? Any my boyfriend was wondering if it goes moldy at all or if it's artificial?

Before I heard about the thermo gun I was going to pick another wall one up but I forgot to.

Also.. what do you guys tend to do with your rats if your snake refuses them? Now that it's summer I don't feel like satan putting it outside but the closest store that sells live ones it pretty far to drive back to the next day to return a $2 rat.

A temp gun would be very helpful to make sure the surface under the bulb is not to hot. When I got a temp gun I found my setup to have surface temps that were to warm even though my air temps were good.

I can't tell if the snake will fit or not for sure. I would guess that it will since your current hide is to big.

The moss I use is from the pet store. It is real. I have never had a problem with it molding. It will get soiled from my snakes and I usually throw away any part of the moss that was exposed to snake excrement. This keeps the moss refreshed in a slow cycle.

I feed refused rats to my garbage disposal, aka blood python. This is where f/t can be very handy. You could kill it and freeze it. I hope once we get your husbandry correct you will be able to feed frozen if you want.