  We study quantum localization phenomena in chaotic systems with a parameter.
The parametric motion of energy levels proceeds without crossing any other and
the defined avoided crossings quantify the interaction between states. We
propose the elimination of avoided crossings as the natural mechanism to
uncover localized structures. We describe an efficient method for the
elimination of avoided crossings in chaotic billiards and apply it to the
stadium billiard. We find many scars of short periodic orbits revealing the
skeleton on which quantum mechanics is built. Moreover, we have observed strong
interaction between similar localized structures.
