Usually, they won't wrap and pull if they are being defensive. I have one baby that when I first got her, was very shy and nervous...She would do repeated-fast-strikes at the prey with no attempt to hold on or wrap. When she got more settled an calm, she then would strike and wrap normally.
If mine want food, they will typically have their neck / head out of their hide, pointed towards the front of the bin. If they are defensive or not interested, they will be completely in their hide or will move away from the feeder.
Your snake striking and wraping the prey is a good sign. You might want to try a slightly smaller prey item or try warming the prey a little more and see if that makes a difference. Sometimes they will just not like a particular feeder also and "reject" it by leaving it.