I need help figuring out what a noise my new glider makes means. I've had my new glider (and my first glider) for a week and I've noticed that the only noise he really makes is a bark/hiss sounding noise. He makes this sound mainly when I'm sitting on the couch at night and he is running in his wheel in his cage. I go over and sit by his cage and he stops making the noise. I don't think it's because he is bonded since it's only been a week. I am just kind of wondering what this sound is and what he is meaning by it. I know it's not crabbing because I have heard his crabbing (even though he's only crabbed twice since I've had him) and this is a very different sound.