My favorite ball "huffs" every single time I pick him up. I call it huffing because they do it with mouth closed, as opposed to open mouth hissing.
He's done it since I brought him home, and continues to do it now. I think he does it because he thinks he is supposed to now. At first he was bluffing, warning big, bad me he could be plenty tough if he had to. Now, I believe he thinks it is expected of him. I'll open his tub, gently lift his hide, and he's looking up at me, just waiting. But as soon as I touch him, he huffs. Once or twice he has almost forgotten to do it, then it's like he suddenly remembers and huffs a little late. It's so cute.
Another of my bigger girls huffs VERY loudly when I go to pick her up, but she never even offers to bite. She's all bark and no bite as the saying goes. I wouldn't let her scare you off. My husband has a little boy, and because it huffed all the time, he was afraid to hold him, now his snake is a mean little monster who snaps at everything. Don't let her bluff turn into something worse.
Gale