Millipedes often evoke curiosity and apprehension due to their appearance and numerous legs. Many people wonder if these invertebrates can bite or are poisonous. Understanding their behavior and natural defenses clarifies these common concerns, distinguishing fact from misconception when encountering them.
The Truth About Millipede “Bites”
Millipedes do not possess mouthparts capable of biting humans in the traditional sense. Unlike centipedes, which have fangs and are predatory, millipedes lack strong mandibles designed for piercing skin. Their mouthparts are suited for chewing and grinding decaying plant material, which forms the primary component of their diet. As detritivores, they feed on decomposing organic matter like dead leaves and rotting wood. This dietary preference further illustrates why biting is not a part of their natural behavior or defense strategy.
Millipede Defense Mechanisms and Their Impact
When threatened, millipedes primarily rely on two defense mechanisms: coiling into a tight spiral and secreting a noxious fluid. Coiling protects their vulnerable underside from predators. More significantly, many species release a fluid from specialized glands, called ozopores, located along the sides of their body segments. This fluid can contain various chemicals, including quinones, phenols, alkaloids, and in some cases, hydrogen cyanide.
The purpose of these secretions is to deter predators, making the millipede unpalatable or irritating. For humans, contact with this fluid typically results in mild and temporary effects. Symptoms can include skin irritation, discoloration, a burning sensation, or temporary staining. Some benzoquinones, for example, commonly cause brown skin discoloration. If the fluid accidentally gets into the eyes, it can cause redness, swelling, and pain, requiring immediate flushing with water. While generally not dangerous to humans, it is advisable to wash hands thoroughly with soap and water after any contact.
Encountering Millipedes
Millipedes often seek damp, dark environments, making basements, crawl spaces, and gardens common places to find them. If encountered indoors, they are generally harmless and easily removed. Gently sweep them onto a piece of paper or into a dustpan for safe relocation outdoors. Millipedes typically do not survive long in the dry indoor environment of a home.
Preventing their entry involves reducing moisture around the home and sealing cracks or openings in foundations and around windows and doors. Millipedes play an important role in ecosystems as decomposers, breaking down organic matter and contributing to nutrient cycling and soil health. Their presence indicates a healthy outdoor environment where they help enrich the soil.