  We observe that quantum indistinguishability is a dynamical effect dependent
on measurement duration. We propose a quantitative criterion for observing
indistinguishability in quantum fluids and its implications including quantum
statistics and derive a viscoelastic function capable of describing both
long-time and short-time regimes where indistinguishability and its
implications are operative and inactive, respectively. On the basis of this
discussion, we propose an experiment to observe a transition between two states
where the implications of indistinguishability become inoperative, including a
transition between statistics-active and statistics-inactive states.
