|Pill bug in its defensive posture|
Armadillidiidae is a family of woodlice, a terrestrial crustacean group in the order Isopoda. They are commonly known as pill bugs or potato bugs. Pill bugs are not insects, but are crustaceans. Crustaceans are animals with hard shells made from many pieces for protection.
Pill bugs look like gray pills. The pill bug's abdomen has seven segments. Pill bugs have flat bodies. The pill bug has three basic body parts called the head, thorax, and abdomen, and they can be many sizes.
The head has eyes (simple and compound) and a mouth. Pill bugs have two sets of antennae. One of the sets is visible to see. The thorax holds the legs. The abdomen holds the exopods of uropods and is attached to some crustaceans' abdomens. Pillbugs eat rotten plants, rotten animals, old garbage, and even bits of food in animal dung. Pill bugs do not breathe through lungs; they have gills. Because of this, they need to be in a damp place or they will die.