The pill bug (Armadillilium vulgare) is a small, segmented land creature that is covered by a hard exoskeleton shell that looks like armor. They have three basic body parts, the head, the thorax, and the abdomen. Pill bugs have 7 pairs of jointed legs and 2 pairs of antennae - but one pair is barely visible. The antennae, mouth and eyes are located on the head. Pill bugs are less than an inch long. Many animals eat pill bugs and the main protection for the pill bug is rolling into a tiny armored ball. They are also called the wood louse or the roly-poly bug, as they are known for this ability to roll into a ball.