The mealworm is a worm-like larva with a hard exoskeleton. Its body is designed to burrow, eat, and store fat. There are three distinct sections which are the head, thorax, and abdomen.
The head of the mealworm has the mouth and labrum, a lip-like mouth part, to aid in its voracious eating habits. The mouth and its parts are quite small and designed to eat small pieces of food.
There is also a pair of antennae and larval eyes. The antennae act as feelers for the worm as it digs in search of food. The eyes are small and poorly developed due to the insect's burrowing nature.
The thorax consists of three segments called the prothorax, mesothorax, and metathorax. Each segment has a pair of short legs. A mealworm doesn't walk very well, but its legs and claws are perfectly suited for burrowing.
The abdomen has nine segments with the last segment containing the anus and a spine. The abdomen contains the digestive tract and stores lots of fat from all the food the mealworm eats. This fat will eventually be used for the worm's transformation into a pupa and then a beetle.