I'm sure most people have had something like this before. I've had these little ticks- some have stayed with me over several years (I'm 15), and some come and go. For example: these days, I'm voluntarily flexing muscles around my heart and stomach, smiling to myself just for the muscle movement, scrunching up my nose, looking up and rolling my eyes as far back as they can see, and shutting my eyes tight for a moment. None of this is because anything is in pain. Could this be because of stress? What can I do about it?