Great news everyone, Sting ate, and totally willingly!
Bought a white adult mouse from Petco tonight and put it in a cardboard box with a paper towel on the bottom with Sting. After about 5 minutes, Sting started looking around, the mouse got too close to his head, and BAM! Dead mouse. He ate it like a champ. I guess our little guy is gonna be ok after all.
Thanks to everyone for your tips and support! I'll be posting here for many years to come I'm sure!