Why are they doing this?

[Kinra]

I have two ball pythons (a pastel and a bee) that seem to have stopped eating. I know this is fairly normal, I don't usually worry about hunger strikes, but both of these girls keep taking the rat like they are starved, strangling it and then not eating it. This combined with the fact that if I re-offer the same rat (without reheating it) they will repeat the process of grab, strangle, ignore and it has me very confused. Usually when I get a snake on a hunger strike they won't show any interest in the food. These girls are taking the food and then just not eating it. They are both 2011 and under 200g. I'm offering f/t rat pups and they spend nights cursing their tubs looking for food. Can someone help me shed some light on this odd behavior please?

Edit:
Since I know it is going to be asked. They are in 17qt tubs on paper towels with hides (sandwich containers painted with non-toxic acrylic paint and air dried). Heat tape is at 94 during the day and 84 at night (they are in a rack with my breeders) so their hot spot is 91-92 during the day and ambient temps on the cool side at 82-84 all the time. They were eating fine until about 3 weeks ago when they started doing this.