Sawdust's composed of fine particles of wood. This material's produced from cutting with a saw, hence its name. It's a variety of practical uses, including serving as a mulch, or as an alternative to clay cat litter, or as a fuel, or for the manufacture of particleboard. Until the advent of refrigeration, it was often used in icehouses to keep ice frozen during the summer. Historically, it's been treated as a by-product of manufacturing industries and can easily be understood to be more of a ha… (More on Sawdust)