Millipedes are invertebrates found across various terrestrial environments. These creatures play a role as decomposers, contributing to nutrient cycling by breaking down dead plant material. They generally prefer dark, damp conditions, which are essential for their survival in diverse ecosystems.
Preferred Terrestrial Environments
Millipedes thrive in environments with high humidity, abundant decaying organic matter, and protection from direct sunlight. Forests, including deciduous and coniferous types, provide ideal conditions with rich layers of leaf litter and decaying wood. Woodlands and gardens also offer suitable habitats, with detritus-rich soil and consistent moisture.
These arthropods are found in agricultural areas and some urban landscapes, adapting to microclimates that meet their needs.
Specific Hiding Places
Within their preferred environments, millipedes seek locations that offer protection and access to food. They are found under rocks, beneath logs, and within thick layers of leaf litter. These spots provide shelter from predators, help maintain moisture levels, and shield them from desiccation.
Millipedes also burrow into the top layers of soil and can be found inside rotting wood, which serves as both a hiding spot and a food source. These microhabitats are important for juvenile millipedes and for adults during molting, when they are more vulnerable.
Environmental Requirements and Global Presence
The distribution of millipedes across the globe is directly influenced by their environmental needs: consistent moisture, moderate temperatures, and decaying organic matter. Millipedes are susceptible to desiccation because most species lack a waxy cuticle and cannot close their spiracles. This requires a continuously moist environment, with substrate that is damp but not waterlogged. Humidity levels typically range from 60% to 80% for many species.
Temperature is an important factor; most millipedes thrive in moderate temperatures, generally between 70°F and 80°F (21°C and 27°C). While tropical species may prefer slightly warmer conditions, prolonged exposure to temperatures below 60°F or above 90°F can be detrimental. Their primary food source is decaying plant matter, such as dead leaves, wood, and other organic debris, making them detritivores in their ecosystems.
These requirements explain why millipedes are most abundant in humid tropical and temperate regions worldwide, including forests where leaf litter and decaying wood are plentiful. They are found on all continents except Antarctica, ranging as far north as the Arctic Circle in some areas. However, their poor dispersal abilities often lead to restricted ranges for many species.
While most prefer humid conditions, some specialized species, like the deserticolous millipedes, have adapted to drier regions by utilizing specific microclimates, such as burrowing deep underground to escape heat and aridity. Conversely, they are absent from extremely arid or frozen environments where these needs cannot be met.