The head has three 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. They also prefer dark rocks or any other dark place to stay that is dark. They are more active at night and early morning because of the darkness. Pill bugs are not beneficial to potted plants. If you notice your potted plants have one or two of them crawling around on the plant, there are probably many more that you don't see feeding off of the roots.