That’s what my doctor said at my last appointment.  “You’ve got a wild one in there!”  She was trying to get a heart beat and was literally chasing him around my tummy.  Just when she would get the beat we would hear a loud thump and the heart beat was gone.  He was kicking the doppler every time.  Of course this would make me laugh which didn’t help matters either.  I don’t think she ever did get a reading that time around but everything was obviously fine.