Sounds like she's defensive striking and not feed striking.

How long have you owned her?

I don't use tongs for live prey. I drop the prey in the opposite end of the enclosure of where the snake is (I don't feed in a separate tub), and if the rat isn't eaten in about 20 minutes, I remove it and house it for another week.

Was it eating live rats, or live mice for the previous owner? If it was mice, it may not convert to rats right away.