Millipedes, with their slow, deliberate movements and numerous tiny legs, often inspire apprehension when encountered. Public concern centers on whether these arthropods are poisonous. Generally, millipedes are harmless scavengers that break down decaying organic matter. This article clarifies their defense mechanism and explains the actual risks associated with contact.
Defining the Danger: Toxic Defense vs. True Venom
Millipedes are not venomous; they do not possess fangs or a stinger to actively inject toxins into another organism. Venomous creatures, like certain spiders or centipedes, must bite or sting to deliver their toxic payload beneath the skin. Millipedes are classified as toxic because they hold defensive chemicals that are released passively upon being disturbed or crushed.
When a millipede feels threatened, its primary defense is to curl into a tight coil, protecting its softer underside. If this fails, specialized glands called ozadenes, located along the sides of their bodies, discharge a noxious fluid. This chemical defense is designed to repel attackers. The amount of toxin released is typically very small, meant to taste bad or irritate the skin of a potential threat.
Understanding Millipede Defensive Secretions
The defensive fluids millipedes release vary widely depending on the species. Many millipedes utilize quinones, which are responsible for the unpleasant odor and staining properties. These quinones, such as benzoquinones, can cause temporary discoloration of the skin, leaving a yellowish-brown stain that may persist for several days.
Some species, particularly larger ones, produce more potent substances, including hydrogen cyanide compounds or organic acids. These aggressive secretions can cause localized skin irritation, known as millipede burn or dermatitis, presenting as redness, itching, or a mild burning sensation. Direct contact with the eyes is serious, as the acidic compounds can cause intense pain, redness, and swelling, necessitating immediate action. While the toxic load is not dangerous to a healthy adult, children or pets who ingest a millipede face a greater risk of gastrointestinal upset.
First Aid and Managing Home Encounters
First Aid Response
If you contact a millipede’s defensive secretion, immediately wash the affected area thoroughly with soap and warm water for several minutes. This ensures the irritating compounds are fully removed from the skin surface. For persistent skin reactions like mild rashes or itching, an over-the-counter corticosteroid cream, such as hydrocortisone, can be applied to soothe the inflammation.
Eye exposure requires urgent response; the eye must be flushed with clean water for at least 15 to 20 minutes, followed by prompt medical attention.
Managing Home Encounters
Managing millipedes in the home is straightforward, as they seek cool, damp areas when their outdoor habitat changes. Removal can be done easily by sweeping them up or using a vacuum cleaner.
Preventative measures focus on reducing moisture and sealing entry points around the foundation. Sealing cracks and gaps in the foundation and around doors blocks access. It is also helpful to reduce outdoor debris near the house perimeter, such as leaf piles, mulch, and decaying wood, as these materials provide the damp, dark conditions they require.