Pill bugs are common invertebrates that are found in many biomes around the world, including temperate forests, rainforests, and grasslands. The pill bug is not an insect but is an isopod. They are more closely related to shrimp and crayfish than to insects and are the only crustacean that has adapted to living their entire life on land. They prefer moist areas, often living in soil and under decaying leaves, rocks, and dead logs. Pill bugs mostly eat decaying vegetable material like vegetables.