Stopping tasting of fingers

Question
Hi,
Is there any way to get my rat to stop "tasting" my fingers? My rat has a habit of periodically biting my fingers, like a few times a day. It never hurts. I am just afraid that she will keep biting harder until she eventually does take a bite of me. Also its a rather disconcerting habit for people who don't know her to experience. Is there any way to discourage her from doing it? I have tried to make sure my hands don't smell too yummy (washing w/ soap before handling the rats), but it doesn't seem to deter her.
Thanks.

Answer
Honestly its a natural behavior and generally a sign of affection, so I don't discourage my rats from nibbling or tasting provided they're gentle. If she gets too rough, exclaim loudly ("OUCH!") and startle her away from it. When she stops, give her a treat and go back to your normal routine. She doesn't WANT to hurt you, she's just being a rat. As for people who don't know rats - explain to them - she won't bite, she's just being a rat.