The Foreign Grain Beetle (Ahasverus advena) is a small stored-product beetle that is unusual among pantry pests in that it feeds primarily on mold and fungal growth rather than on the grain or food itself. Adults are tiny (1/16–1/8 inch), reddish-brown, and flattened, with a distinctive small projection or 'tooth' on each front corner of the thorax — visible under magnification. The Foreign Grain Beetle is found in stored grain, flour, and other food products that have become damp and moldy, in new construction where green lumber and drywall support mold growth, and in any area with moisture problems and associated mold. In Arizona homes, the Foreign Grain Beetle is often encountered in newly constructed or recently renovated homes where moisture in building materials supports mold growth — the beetles feed on the mold and are not actually infesting food. They are also found in damp pantries, basements, and storage areas where moisture has caused grain or food products to mold. Because they feed on mold rather than food directly, the presence of Foreign Grain Beetles is often a diagnostic indicator of a moisture problem rather than a food storage problem.