Centipede vs Millipede

Both are long, many-legged, segmented animals that turn up in basements, mulch and under logs, so they get mixed up constantly. Neither is an insect. Both belong to a group called myriapods, and neither has exactly 100 or 1,000 legs, despite the names. Centipedes range from 15 to 191 pairs of legs, so their numbers vary by species.

The practical difference is behavior. A centipede is a hunter that kills insects with venom, moves quickly and may bite when handled, which can feel like a bee sting. A millipede eats decaying plants, moves slowly, curls up when disturbed, and can release a foul-smelling fluid that may irritate skin.

Centipede vs Millipede side by side

Last verified October 2026. Typical values; individual animals, products and local prices vary.

When you are looking at which

Centipede

• The animal sprints away the moment you lift a rock or turn on a light.
• Each segment has a single pair of legs sticking out from the sides.
• The body looks somewhat flattened and the animal is clearly a hunter chasing prey.
• It bit or pinched someone who handled it.

Millipede

• It moves slowly and curls into a tight coil when touched.
• Each segment seems to have two pairs of legs, directly under the body.
• It looks rounded and is found in damp mulch eating rotting leaves.
• It left a smelly fluid on your hand but did not bite.

How this works

The quiz uses five cues from museum and nature-center guides: movement, leg pairs per segment, body shape, what the animal is doing, and how it reacts to touch. The leg count is the most reliable, while the others support it.

It sorts the two groups, not species. House centipedes, giant tropical centipedes and tiny soil millipedes all fit the pattern, but sizes and leg totals vary widely. If the animal is unusually large or you have a bite with a bad reaction, get advice from a local expert or doctor.

Where these numbers come from

The figures and defaults on this page are based on:

• Carnegie Museum of Natural History: Centipede or Millipede? What's the Difference?, Leg placement, body shape, diet, defense and habitat of the two groups (checked October 2026)
• Australian Museum: Centipedes and millipedes, Leg-pair range for centipedes, legs per segment and myriapod classification (checked October 2026)
• Reconnect with Nature: Centipede vs. millipede, Behavior when disturbed, diet, bite or irritant risk and species counts (checked October 2026)

Field-identification guide to the two groups; species vary widely, so seek local expertise for large specimens or medical advice after a bad reaction.