Mealworms hibernate as larvae, digging tunnels in various substances, particularly wood. The larva and adults live in dark, hidden places and feed on corn, wheat, flour, and grains, especially the germ. Adults can also feed on meat.

Mealworms are often found in grain mills and farm buildings, where they infest animal feed. In houses, mealworms mainly feed on decomposing organic matter. They are often found in and around birds’ nests or in garbage chutes.