If female guinea pigs go through heat.

Question
My female guinea pig is nibbling on my hand and fingers so My question is:
Can this be because she is in heat?
Do you know why else she would be doing this?

Answer
it means she likes you. :-) also I really can't answer the question about her being in heat because guinea pigs generally breed anytime of the year if you put them with a mate, but please don't do that. She just likes you and is showing affection. Have you had her purr yet? It's a very cool thing to hear.