In my experience, carpets are always in motion. All of my guys cruise around and explore while I'm holding them. Voodoo will come out of his cage when I open the door and usually crawl right onto my shoulders, but then he's all over the place- looking around, stretching, craning his neck to check things out. They are always a handful, but so much fun. Sooo much personality, or "snake-onality" as I call it.
Also, I've noticed that, when excited, carpets huff and breathe loudly. It's not quite a hiss, not quite not. But there's no aggression too it; I would liken it to a dog panting from being excited about something. Only my carpets do it, but they all do and I've never seen a tensing or a strike. Just the half-hiss/huff when they come out and explore.