Abstract: In this talk, we discuss a basic (and somewhat classical) problem of Laplace eigenfunction mass concentration on convex polyhedra. We show quantitative mass concentration in a neighbourhood of the non-smooth part of the boundary, or the "pockets" of the billiard. Mainly standard microlocal analysis and control theoretic tools are used, but on the way, we also discuss several new dynamical properties of the billiard flow on polyhedra which are required for the proof.