Rolly pollies, recognized for curling into a tight sphere, are also known as pill bugs and woodlice. These small creatures are not insects, but terrestrial crustaceans, more closely related to crabs and shrimp. They are found worldwide in temperate terrestrial ecosystems, thriving in gardens and other damp environments.
Daily Habits and Diet
Rolly pollies prefer dark, moist environments, often found under rocks, logs, leaf litter, and garden mulch. They are primarily nocturnal, remaining inactive during daylight hours to conserve moisture and avoid desiccation. This hidden lifestyle helps maintain the damp conditions their gill-like respiratory structures require.
These creatures are detritivores, meaning their diet consists mainly of decaying organic matter. They forage on dead leaves, rotting wood, fungi, and sometimes decaying plant roots. Their tiny mouthparts are well-suited for munching on soft, decomposing plant material.
Beyond plant matter, rolly pollies also consume dead insects and other decomposing animal remains, acting as scavengers. They use their two pairs of antennae, equipped with sensitive hairs, to navigate their surroundings and locate food sources through touch and smell. This foraging behavior contributes to their broader ecological functions.
Their Role in Ecosystems
Rolly pollies play a significant role in ecosystems as primary decomposers. By consuming decaying organic matter, they break down complex materials into simpler substances. This process helps return essential nutrients, such as nitrates and phosphates, to the soil, enriching its composition and making these nutrients available for plants.
Their feeding and movement through the soil contribute to soil aeration, allowing air, water, and nutrients to circulate more effectively. This action enhances soil structure and overall health, supporting plant growth and the wider ecosystem. Rolly pollies also help control harmful fungi and bacteria within the soil.
They can safely remove heavy metals from the soil. They achieve this by crystallizing toxins like lead, cadmium, and arsenic within their guts, preventing these substances from leaching into groundwater. This capability helps clean up contaminated soil and protects water sources.
Why They Curl Into a Ball
The behavior of rolly pollies curling into a tight ball, known as conglobation, serves as a primary defense mechanism. When disturbed or threatened by predators such as spiders, centipedes, birds, or small mammals, they quickly transform into a compact sphere. This action protects their vulnerable underside and delicate gills by presenting a hard, armored exterior.
Conglobation also plays a role in moisture conservation. Rolly pollies breathe through gills, which require constant moisture to function. By rolling into a ball, they reduce their exposed surface area, minimizing water loss and preventing desiccation, particularly in dry or open environments. This behavior helps them survive.
This ability to roll up completely is why they are commonly referred to as “pill bugs” or “rolly pollies.” It is an effective evolutionary adaptation that combines physical protection with moisture maintenance for their terrestrial existence.