Centipede: How to Identify One, Whether It Bites, and How to Keep It Out

What is a centipede?

A centipede is a fast, meat-eating arthropod with a long, flat body and one pair of legs on each segment. The first pair of legs is shaped into venom claws for catching prey. Scientists call the group Chilopoda. Most adults are brownish and over 1 inch (25 mm) long.

Centipedes hunt other small animals, mostly insects and spiders. They live in damp, dark places: under stones, leaf litter and logs outdoors, and in basements, closets and bathrooms indoors. During the day they hide in cracks, and at night they come out to hunt.

You can tell a centipede by four things. First, it runs fast. Second, its legs stick out to the sides, one pair per segment. Third, it has long antennae. Finally, it never coils up when you disturb it. A millipede does the opposite on all four counts.

There are about 3,300 to 3,500 known species worldwide. The world catalogue of centipedes, ChiloBase, counted 3,332 valid species in 2016, and other references put the figure between 3,000 and 3,500.

How many legs does a centipede have?

A centipede has between 15 and 191 pairs of legs, which is 30 to 382 legs. The number of pairs is always odd, so no centipede has exactly 100 legs. The house centipede has 15 pairs, or 30 legs. UC IPM says most species have closer to 30 legs than to 100.

Centipede means “hundred feet”, and like the millipede’s name, it is not literal. The Missouri Department of Conservation states the range as 30 to 382 legs, always in odd numbers of pairs.

Why the pairs are always odd

Every centipede ends up with an odd number of leg pairs, from 15 up. The Missouri Department of Conservation says the pairs are always in odd numbers. So when Britannica gives a range of “14 to 177 pairs of legs”, the 14 cannot be right. The current figure is 15 to 191.

Is a centipede an insect?

No. A centipede is not an insect. Insects have 6 legs and three body parts. Centipedes have 30 or more legs and a long body of many segments. They belong to the class Chilopoda, in a group called myriapods that also includes millipedes. Both are arthropods, like insects, spiders and crabs. Our insect identifier explains where each group sits.

Types of centipedes

Centipedes fall into five main groups, or orders. In US homes and yards you will meet four kinds: the house centipede, stone centipedes, soil centipedes, and in the south and southwest, the big Scolopendra centipedes. The giant redheaded centipede reaches about 8 inches (20 cm). The house centipede is the only one that breeds indoors.

The five groups of centipedes

Centipedes are divided into five orders. House centipedes belong to Scutigeromorpha, stone centipedes to Lithobiomorpha, and soil centipedes to Geophilomorpha. The big tropical and desert centipedes belong to Scolopendromorpha. A fifth group, Craterostigmomorpha, has only two species, one in Tasmania and one in New Zealand.

The house centipede

The house centipede, Scutigera coleoptrata, is the one most people find indoors. Its body is 1 to 1 1/2 inches long, dirty yellow with three dark stripes, and it has 15 pairs of banded legs. The legs and antennae are so long that the whole animal looks 3 to 4 inches long. It is native to the Mediterranean and spread across the US from the south.

It is the only centipede species that lives and reproduces in homes. In colder states it cannot survive winter outdoors, but it breeds readily in heated buildings. So if you see them all year, a small population is living with you.

Stone centipedes and soil centipedes

Stone centipedes are the shorter-legged centipedes you find under mulch, leaves, loose bark and stones. They have 15 pairs of legs as adults, grow up to about 2 inches, and are harmless to people. Soil centipedes are very slender and completely blind, with 29 or more pairs of legs. Both kinds wander indoors now and then, but they die quickly in dry buildings.

The giant redheaded centipede

The giant redheaded or giant desert centipede, Scolopendra heros, is the big one of the southern and southwestern US. It has a black body, yellow legs and a rusty-red head, and is often 6 inches long. Arizona populations are reddish-yellow with dark bluish-black stripes. Sources disagree on its top size, from about 8 inches to over 9.

They also disagree on the bite. Arizona Extension calls it about as serious as a bee sting. The Missouri Department of Conservation says it can be intensely painful and cause swelling, though usually no worse than a wasp or scorpion sting. Either way, do not pick one up. Arizona Extension suggests kitchen tongs or heavy gloves and a covered jar to move one outside.

Black centipedes

A black “centipede” is often not a centipede at all. If it is shiny, slow and curls into a spiral, it is a millipede. A fast black centipede with yellow legs and a red head, in the southern US, is the giant redheaded centipede. Leave that one alone, because its bite can be very painful.

Small centipedes

A small centipede indoors is usually a young house centipede. They hatch with only 4 pairs of legs and add more as they grow. Outdoors, small brown ones under stones are stone centipedes. A tiny white “centipede” under 1/4 inch in garden soil is likely a symphylan, which is not a true centipede.

The garden centipede

The “garden centipede” is usually a symphylan. These are white, less than 1/4 inch long, and have 12 pairs of legs as adults. They are not true centipedes. Unlike centipedes, they can attack the roots and underground parts of plants, especially in damp soil rich in organic matter.

The biggest centipedes in the world

The largest is Scolopendra gigantea, a giant centipede of the American tropics. It reaches about 280 to 300 mm (11 to 12 inches). In the US, the giant redheaded centipede, at up to about 8 inches (20 cm), is the largest you are likely to meet.

Centipede or millipede?

A centipede has 1 pair of legs per segment and runs fast. A millipede has 2 pairs of legs on most body rings and moves slowly. Centipedes hunt other bugs and can bite, while millipedes eat dead leaves and cannot bite. If it curls into a flat spiral, it is a millipede, not a centipede.

One more check: a centipede’s last pair of legs points backward, which a millipede’s does not. For more on the slow, curling one, see our guide to millipedes.

Do centipedes bite? Are they dangerous?

Centipedes can bite, because the first pair of legs is a set of venom claws. A bite causes pain, redness and swelling, and the pain usually lasts from 30 minutes to 3 days, according to StatPearls. Still, centipedes are generally harmless, and the house centipede rarely bites. Serious reactions are rare.

Does a house centipede bite?

Rarely. According to the University of Arkansas, the house centipede’s jaws are not powerful enough to break human skin easily, and a bite is no worse than a bee sting, and a house centipede biting a person at all is very rare.

What a centipede bite looks like and feels like

The most common symptom is pain at the bite, followed by redness or bruising and swelling, according to StatPearls. MedlinePlus says symptoms most often last less than 48 hours, although swelling and tenderness can last up to 3 weeks. A bite from a large Scolopendra hurts the most.

A bite mark alone cannot tell you which creature bit you. Many bites and skin reactions look alike, as our bug bite identification chart shows. So if you did not see the centipede, treat the mark as an unknown bite and watch for the warning signs below.

First aid for a centipede bite

Wash the bite with plenty of soap and water, as MedlinePlus advises, and do not use alcohol on it. Then put ice wrapped in a clean cloth on the bite, 10 minutes on and 10 minutes off. Poison Control notes that ice packs reduce the pain. It also says to check that you have had a tetanus shot in the past 10 years, because a bite is a puncture wound.

Can a centipede bite kill you?

Deaths are extremely rare. Sources disagree on whether any have happened in the US. StatPearls reports 6 US deaths linked to centipede bites between 1979 and 2001. MedlinePlus says the bites are not fatal, and Poison Control says deaths have happened mainly in tropical areas outside the US. Overall, StatPearls calls the outlook after a bite excellent.

Are centipedes dangerous to dogs and cats?

The house centipede is not. It does no harm to structures, stored products, fabrics, pets or people. A large Scolopendra is different, because its bite is painful even for a person. If a pet is bitten by a big centipede and shows swelling, drooling or distress, call your vet.

Why do I have centipedes in my house?

Centipedes come indoors for 2 things: moisture and food. They need damp air, and they eat the insects and spiders already living in your house. One or two in a damp basement or bathroom are normal. Large numbers of house centipedes usually mean plenty of prey, such as silverfish, cockroaches or spiders.

House centipedes are found where humidity is high, and they move in when basements or sub-floor areas are damp. Basements, cellars and first-floor bathrooms are their favorite places.

What does a house centipede tell you about your house?

It tells you there is food. Its prey includes silverfish, firebrats, carpet beetle larvae, cockroaches, spiders, crickets, bed bugs, flies, moths and earwigs. So many house centipedes usually means many of these. If you see a lot, look for silverfish, carpet beetle larvae, cockroaches and common house spiders next.

Why is there a centipede in my bathroom or bedroom?

Bathrooms are damp, which suits them. Bedrooms come up because centipedes hunt at night and pass through any room. A centipede on a wall or a bed is hunting insects, not people. They hide in cracks by day and come out after dark, so night is when people meet them.

Should you kill a house centipede?

You do not have to. UC IPM calls house centipedes beneficial, because they catch flies, cockroaches and other small household pests, and they never damage plants or household items. If you can live with one or two, they are working for you. If you cannot, catch it under a cup or vacuum it up.

Centipede life cycle and lifespan

Centipedes live a long time for a small animal. UC IPM says they take 2 to 3 years to mature and have been known to live 6 years. The Connecticut Agricultural Experiment Station says the house centipede can live up to 7 years, and the Missouri Department of Conservation says some centipedes live over 10.

Most centipedes lay eggs in damp soil in spring and summer. The female house centipede lays 35 to 100 eggs and does not guard them, and one female can produce up to 150 young.

Young house centipedes hatch with only 4 pairs of legs. They then have 5, 7, 9, 11 and 13 pairs over the next five molts, and 15 pairs after that. Stone centipedes also add legs as they grow. In contrast, soil centipedes and the big Scolopendra species hatch with all their legs. The females in these groups stay with their eggs.

How to get rid of centipedes

To get rid of centipedes, take away the 2 things they need: moisture and food. Run a dehumidifier in damp rooms, fix leaks, seal cracks behind baseboards, and clear clutter. Then cut down the insects they eat, and set sticky traps. University of Minnesota Extension says pesticides fail while moisture and food remain.

All of the first steps are cheap or free, and they solve the cause rather than the symptom.

Step 2 is the one most people skip. The centipedes are there for the prey, so our silverfish guide and German cockroach guide cover the two most common food supplies indoors.

Natural ways to keep centipedes away

Dry air is the most natural repellent there is. If the moisture and the prey are gone, centipedes leave or die out on their own. If exclusion and drying are successful, insecticide treatments are not required. Try non-chemical control first, and use a pesticide only if none of the other methods work.

What does not work

Most of what fails against centipedes targets the centipede and ignores the cause. A house with damp rooms and plenty of insects will keep drawing them in, whatever you spray. Here are 6 common beliefs, and what the experts say instead.

• Myth 1

  Myth: “Spraying will get rid of them.”

  Truth: University of Minnesota Extension says pesticides are not effective if there is too much moisture and a food supply. UC IPM calls their use rarely justified.

• Myth 2

  Myth: “Centipedes have 100 legs.”

  Truth: UC IPM says most species have closer to 30. No centipede has exactly 100, because the pairs are always odd.

• Myth 3

  Myth: “A house centipede bite is dangerous.”

  Truth: Its jaws rarely break human skin, and the University of Arkansas compares a bite to a bee sting.

• Myth 4

  Myth: “Killing the centipedes solves the problem.”

  Truth: They are a sign of other bugs. Without fixing the damp and the prey, new ones move in.

• Myth 5

  Myth: “A bug bomb will clear them out.”

  Truth: Ohio State University Extension says total-release aerosols, the so-called bug bombs, are ineffective against centipedes.

• Myth 6

  Myth: “Centipedes are insects.”

  Truth: They are myriapods, with 30 or more legs, not 6.

When to call someone

Most centipede problems are solved with a dehumidifier and some caulk. Call a professional when centipedes keep appearing after you have dried and sealed the house, because that points to a larger pest problem. For a bite, call Poison Control at 1-800-222-1222, or 911 for trouble breathing.

Not sure it is a centipede? Upload a photo to our free bug identifier for an answer in seconds.

Pest control disclaimer. Photo-based identification can help, but it is not always perfect. For dangerous spiders, large infestations, or anything you are unsure about, contact a licensed pest control professional.