Is it mad at me?

Question
I just bought a cage mate for my female guinea pig today. When I pet her, he shakes and makes a purring noise, but I'm afraid to pick her up. It seems like she might swing her head around and bite me. Can you help? What are some signs that a guinea pig is angry and will bite you?

Answer
Hello Meaghan,
If you show your guinea that you are afraid it will become scared of you. Show whos boss in a firm but friendly way. It could be a behavioural problem or a medical one. Maybe her tummy hurts so she doesn't like you picking her up? If you have other pets make sure you wash your hands before touching you guineas. Your old guinea may feel that the new guinea is a predator and may smell of male guineas. Try introducing the guineas together before housing them. They may just not like eachother.
Love Aleksandra