Size: Larval mealworms usually measure between ⅛-1 inch long with ½ inch being the average.
Color: Adults are dark with a hard shell. The mealworms themselves (larval form of the beetle) are yellowish-brown with ringed, segmented bodies. They may look darker near the ends of their abdomen and head, and near each of their grooves or segments.
Body: Mealworms have evenly divided grooves resembling body segments running along the whole length of their abdomen.