Adults are small, flattened, reddish brown beetles about 3.5 mm in length. Key identifying characteristic is that the antenna enlarges into a club consisting of four segments.
Confused flour beetles feed off grain dust found in flour mills, but also infest cereal products and pet foods and are commonly found in grocery stores and food warehouses. These beetles are carried into homes in infested cereals, flour, and pet foods and can then spread to other foods in the cupboard. Unable to feed on undamaged grain, they act as a secondary feeder to other insects such as rice weevils.
They are capable of breeding throughout the year where buildings are warmed, but only adults are found inside unheated buildings. Eggs are whitish or colourless and are covered by a sticky material which particles of flour adhere to, making them very difficult to spot.