Millipede Identification & Control

Quick Identification

• Size: About 1–1.5 inches long
• Color: Dark brown to black
• Key Features: Cylindrical body with two pairs of legs per segment (centipedes have one pair); slow-moving; curls into a spiral when disturbed; may release foul-smelling secretion
• Habitat: Outdoors under leaf litter, mulch, rocks, decaying wood. Enters homes during heavy rain or drought.
• Active Season: Spring through fall
• Risk Level: None — harmless nuisance; does not bite or sting

What You Need to Know

Millipedes are slow-moving, harmless decomposers that feed on decaying plant material outdoors. They become a household concern during two specific weather conditions: heavy, saturating rains that flood their ground-level habitat, or prolonged drought that drives them to seek moisture. During these events, millipedes can enter homes in surprisingly large numbers through foundation cracks, basement windows, and garage doors.

The Illinois Department of Public Health notes that millipedes often die indoors because moisture and food sources are insufficient. They don’t bite, don’t breed indoors, and don’t cause structural damage. When disturbed, some species release a mildly unpleasant secretion as a defense mechanism. The primary concern is the nuisance of finding dozens of slow-moving, curled-up arthropods in your basement.

The easiest way to distinguish millipedes from centipedes: millipedes are cylindrical and slow with two pairs of legs per body segment. Centipedes are flattened and fast with one pair per segment. Reducing mulch, leaf litter, and ground cover near your foundation limits the population available to invade. Sealing foundation cracks prevents entry. Contact Sanctuary Pest Control at 815-993-3472 for perimeter treatment if invasions are recurring.