That's exactly how mine behave, if they see something new they approach slowly, with their tails swishing slowly like a snake making a moving S shape. If they're alarmed or in a fight the tail will go faster. If I stroke mine they will raise their tails up over their backs.
We need a Dr Doolittle to join the board, it would great to know what they really think. I'm not so sure they really like being stroked on their backs, their sides and their noses mine seem to like.