The merchant grain beetle, Oryzaephilus mercator, is a slender, dark brown beetle. It can be found infesting biscuits and fruit and nut products. The adults can fly but rarely do. They can be differentiated from Oryzaephilus surinamensis by looking at the distance of the eye to the prothorax: with the merchant grain beetle it is less than half the vertical diameter of the eye. Like O. surinamensis, they are distributed throughout the world and regularly transported to consumers in unprocessed cereals, oil cakes, and from grains from other stores.