A bite/wrap is a food response. After you wash your hands use something like lemon-scented hand sanitizer on them, the smell will make her less likely to grab you. This is also the time of year when females start pounding the food in preparation for breeding season.

What size are these "small" rats? If you're getting the Arctic Mice brand from a pet store they are only 50 grams, so they're on the very small side of the smalls. If that's the case try feeding her two or bump her up to mediums.