Fauna
Invertebrate · GBIF taxon 1027554

American Giant Millipede

Narceus americanus

Also known as Worm Millipede, Iron Worm, Giant North American Millipede

American giant millipedes play a critical role in eastern forests by breaking down rotting wood and leaf litter into rich topsoil. When threatened, these smooth, dark arthropods tightly coil their body to shield vulnerable legs and underside. They are most active during warm, humid weather when they forage along damp woodland floors.

DetritivoreNocturnalForest Dweller
American Giant Millipede reference
Licensed reference(c) Judy Gallagher, some rights reserved (CC BY) · cc-by
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & prey
  • Decaying wood, fallen leaves, organic matter
Predators
  • Birds
  • Toads
  • Small Mammals
ThreatsHabitat destruction, deforestation, severe drought
HabitatsDeciduous forests, damp woodlands, decaying logs
Life span2–11 years
Classification
  1. OrderSpirobolida
  2. FamilySpirobolidae
  3. GenusNarceus
  4. SpeciesNarceus americanus
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Secretes an irritating fluid that stains skin; avoid touching eyes and wash hands after handling.
Why it is dangerous
Secretes benzoquinones from specialized lateral glands when threatened, which can cause mild chemical burns and temporary skin discoloration.
How to recognize a risky encounter
Recognizable by its large, cylindrical dark grey or brown body featuring reddish accents along segment edges.
What to do
Keep away from eyes and mouth, and wash skin thoroughly with soap and water if handling occurs.
Responsible observation
  • Observe in Place: Watch them explore decaying logs without removing them from their shelter.
  • Gentle Touch: Allow the millipede to crawl freely across flat, open palms without restraint.
  • Wash Hands: Clean hands with soap immediately after contact to prevent minor skin staining.
Related species
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