Pill bugs breathe using gills. Consequently, they are restricted to damp, humid habitats. They are frequently found in forests and gardens under logs, stones, leaf litter, pavers and flower pots. They are also common in basements. Temperature between 59 and 66 degrees Fahrenheit are ideal. The reproductive potential and size of the species are largely dependent on moisture and pH levels of the soil. Too much or too little moisture as well as pH levels outside their preferred range can significantly limit the survival rates of pill bugs.
Food requirements vary by stage of life. Adult pill bugs are omnivorous organisms that feed on fungi, tender foliage of living and dead plants, and animals. In general, they prefer dicot food sources to monocot ones. Pill bugs process their food through their alimentary canal. The resulting fecal matter is consumed by young pill bugs. Pill bugs are most active at night. They are known to feed on seedlings, bedding plants and the roots of young plant transplants. They may attack vegetables lying on the ground, causing the vegetables to become deformed.
Pill bugs grow larger and reproduce faster when food availability and temperatures are optimal. Low temperatures and poor food quality result in small pill bugs that are not produced until the final year of the adult female's three-year life. Aside from pH levels of the soil, pill bug survival is also highly related to levels of soil bacteria, leaf toughness, the nitrogen to carbon ration of the soil as well as the presence of secondary chemicals such as tannins.
Pill bugs aid decomposition of dead plants and animals. They also serve as a food source for other animals. In their immediate area, they slightly improve soil through aeration. In addition, they may influence soil properties in the topsoil layer. The presence of pill bugs is thought to increase pH, phosphorus and potassium, and decrease carbon levels. Overall, however, most gardeners consider this species a nuisance because of the damage they inflict on new, tender plant tissue. Considerable damage to new plantings and transplants may occur where a large pill bug population exists.