Head to head
House Centipede vs Giant African Millipede
Centipedes and millipedes are both long, many-legged arthropods in the group called myriapods, and both turn up under logs and stones and in damp corners of houses, so they are constantly mixed up. But they are different classes of animal with opposite lifestyles. One is a fast, flat, venomous predator; the other is a slow, round, harmless recycler of dead leaves.
| House Centipede | Giant African Millipede | |
|---|---|---|
| Legs per segment | One pair | Two pairs |
| Leg position | Splayed out to the sides | Tucked underneath the body |
| Body | Flattened | Rounded and tube-like |
| Speed | Fast | Slow |
| Diet | A predator: insects, spiders, other invertebrates | A detritivore: decaying leaves and wood |
| Weapon | Venomous fangs (modified front legs) | Curls up and releases noxious chemicals |
| Risk to people | A bite; painful in larger species, minor in house centipedes | Skin and eye irritation from the defensive fluid |
| Leg count | 15 to 191 pairs, always an odd number of pairs | Dozens to over 1,300 legs |
Centipede vs Millipede: common questions
What is the easiest way to tell a centipede from a millipede?
Count the legs on one segment if you can, or just look at how the legs sit. A centipede's legs project out from the sides of a flat body, giving it a fringed, oar-like look, and there is one pair per segment. A millipede's legs are short and packed close together underneath a rounded body, moving in flowing waves, and there are two pairs per segment. Behaviour is a quick backup: a centipede darts away when disturbed, while a millipede slows down and curls into a coil.
Which one bites?
The centipede. Its front pair of legs is modified into curved, hollow claws called forcipules that inject venom, used to subdue prey and in defence. A bite from a large tropical centipede is genuinely painful, with swelling and, rarely, more serious reactions, though deaths are extremely rare. The common house centipede can bite if handled roughly but usually cannot break human skin and is not considered dangerous. Millipedes have no biting mouthparts capable of harming a person and no venom; the worst they do is stain and irritate skin with their defensive secretion, which in some large species contains compounds that can blister.
Do any centipedes or millipedes actually have 100 or 1,000 legs?
No. Centipede means "hundred feet" and millipede means "thousand feet", but both are misnomers. Centipedes have between 15 and 191 pairs of legs, and because the number of leg-bearing segments is always odd, no centipede has exactly 100 legs. Millipedes were all under 750 legs until 2021, when a species from deep underground in Western Australia, named Eumillipes persephone, was found with up to 1,306 legs, the first true "thousand-legger" and still the only one known.