Doodling- a mind altering drug?

I've always doodled at times I should be paying attention to something else. Put me in front of a teacher and I'll be doodling within moments. When my wife was recently hospitalized, The only way I could control my tension was to fish a small pad out and start in. The faces don't necessarily reflect my mood, just some sort of inner dial saying- draw a growling face, now a smiling one, now a laughing guy, now a shout. I draw weird bird when I feel self conscious about always doing another face.