My lavender, Damballah, rattles his tail and strikes at me every time I put my hand in his viv. But he also rattles the entire time he's eating. Even if I leave the room, I can hear his little tail buzzing on the side of his feeding tank. He's got quite an attitude on him. He's never bitten me, but I've had him for over a year and he still doesn't like me. The odd part is that once I get him out of his viv, he likes being handled. He just doesn't like my hand in his viv I guess.
My amber corn, on the other hand, has never rattled (at least not that I've ever seen).