American Giant Millipede

Millipedes like the one in this photo (Narceus americanus) are commonly found in forests, gardens, and even sidewalks or driveways—basically anywhere that stays somewhat humid. Even if it wasn’t on damp wood, it probably came from a nearby moist area like soil, mulch, or leaf litter and just wandered out.

They’re detritivores, meaning they eat dead leaves, rotting plants, and organic debris, not live plants or animals. When they feel threatened (like when you got close), they curl into that tight spiral you saw—that’s their main defense. Some can also release a mild chemical secretion that smells weird and can irritate skin a bit, but nothing dangerous.