We propose an alternative concept of heat manipulation based on the particle picture of phonons and their ballistic transport. We call this concept ray phononics, as a thermal analogue of ray optics. Our Monte Carlo simulations show that stochastic phonon motion in silicon phononic crystals tends to form directional heat fluxes at low temperatures. We use such directional heat fluxes to demonstrate different ways in which heat can be passively focused into a single spot. We also show that heat emitted from a single hot spot can be collimated into a parallel thermal flux. Such collimated fluxes can be directed in the desired direction or split into multiple fluxes. These effects enable platforms where heat fluxes can be directed and manipulated in a similar way to light beams on an optical stage. Using this concept, we propose several conceptual devices such as beam splitters, delay lines, beam displacers and diffusers.