Strange behavior and aggression?

Okay so Ive had my bp for about nine months. She has been amazingly docile and I have been able to do anything with her. I moved a few months ago and I havent been able to handle her daily like I used to. She was acting completely normal until about a month ago. First she just started yawning alot, then she would bump her nose to my arm and open it like she was going to bite my arm. And over the past week she has been in striking position everytime I open her cage. About 5 minutes ago she was striking at the side of the cage even though there was nothing there.

I have been feeding her and her environment is fine so I dont know what could be wrong.

Help?

Excessive yawning and face rubbing are two symptoms of a Respiratory Infection. Have you noticed her laying with her head elevated alot? Other signs are wheezing and popping noises when she breathes, mucus or bubbles in the mouth, dried mucus around the enclosure where she's been rubbing her face, trying to clear her mouth. Might be time to schedule a vet appointment...

What size prey are you feeding her?

Ive thought about a respiratory infection but she isnt showing any signs of it at all. Right now im feeding her small to medium rats. She is about 4 feet long.