Why is my guinea pig biting, can I make her stop

My guinea pig,Angel, is 9 months old and she bites me if my hands are near her mouth. Some times if I put food in her cage she bites my hand. Her bites hurt sometimes, and sometimes she can make you bleed! Does anyone know how to make her stop biting?I assume she bites fingers because she loves carrots and to her they may look the same. But when I let her socialize with my friends guinea pigs Belle, and Jeep (both girls who dont bite) she runs to their sides and I think she is biting them? I am not sure if she is biting or mating, but she can't mate with another girl?What is happening?I want her to stop!Is this common?Someone help?

Firstly you need to handle her for app 10 minutes a day each day along with 1 hour of floor room, at the least. What size is your cage, it should be at least 7.5sq ft. The 2 main things for biting include:

1. Mites

2. Fear

It would not hurt to take your pigger to the vet for a general examination, if she has mites then she needs the appropriate treatment. You can treat her from home but if you accidently overdose she could die.

Guinea pigs are social animals by nature, they should be housed in groups of 2 or more, you will find that Angel will be more active and generally happy. As for your friends guinea pigs coming over, they are not there 24/7 as a companion would be so I do not think she really is getting much socializing, besides guinea pigs are not good travellers.

So, handle, floor time, expand cage, go to the vet, get her a companion, and see what happens from there.