Under the bark of a fallen oak in a Florida hammock, in the damp dark underneath where the wood is soft and the insects are thick, there lives an animal that looks like it was painted by someone with two pots of paint and no interest in subtlety. The Florida blue centipede, Scolopendra viridis, is a blue-centered, orange-edged centipede, three to four inches of fast, flattened predator, and it is the large centipede a Florida gardener is most likely to actually meet. It is also the animal at the center of the most confusing name in this whole library — because “Florida blue centipede” is the common name of two different species, and this guide is about sorting them out.

And if you are reading this in Florida because you just found a fast, blue-and-orange centipede under a log and want to know whether to panic — stay with us. The short answer is no, with one rule attached: do not pick it up. It can deliver a painful bite, it is fast enough to surprise you, and everything else in this guide — what it eats, what it does for your garden, how to keep it out of your house — follows from that one rule.

What it looks like

Start with the size, because the size is the first check against the other animals that share its name. An adult Florida blue centipede is typically about 3 to 4 inches long — 75 to 100 millimeters — with 21 pairs of legs, and large adults can reach about five and a half inches: one Florida specimen measured for a venom study was 13.8 centimeters long. That makes it a medium-large centipede — bigger than any bark centipede in the East, smaller than the Giant Red-Headed Centipede of Texas, which reaches twice its length.

The color is the field mark, and it is a good one when it shows. The center of each body segment is dark blue, greyish-blue, or violet-blue, while the outer edges of the segments are a contrasting orange or reddish color. The legs are usually a paler orange or yellow, and the underside is a deeper orange or red. That blue center with orange margins is the look that gives the animal its name — but fair warning, this species is famously variable. It occurs in several color forms, including a striking “blue-striped” form with a brown to pale-white body and a single electric-blue stripe running down the back from head to tail, and some individuals are much greyer, browner, or more orange than blue. The blue varies. The size, the flattened body, the 21 leg pairs, and the fast, darting movement do not.

The body is flattened top-to-bottom, as all centipedes are, with long legs sticking out sideways from each segment. The last pair of legs is longer than the rest and trails behind like a second set of antennae — a detail that makes people think the centipede has two heads. The real head is the end with the short antennae. Just behind the head sits the pair of venom fangs called forcipules: modified front legs, hollow like hypodermic needles, connected to venom glands in the body trunk. Those are the business end. Everything else about this animal — the speed, the armor, the color — exists to get those fangs onto prey.

The name game (two Florida blues — this one and the other one)

Here is the confusion, stated up front, because this guide is useless if it does not sort it out. The name “Florida blue centipede” is used for two different animals. This one, Scolopendra viridis, is the one most sources mean when they say “Florida blue centipede” — it is also called the giant Florida blue centipede. The other one is Hemiscolopendra marginata, a smaller eastern bark centipede that is also called the Florida blue centipede, and also the eastern bark centipede. The two are related — both are scolopendromorph bark centipedes — but they are different species, different sizes, and different animals, and half the photos labeled “Florida blue centipede” on the internet are the other one.

The checks are simple. Size first: S. viridis is 3 to 4 inches and up; H. marginata tops out around 3 inches. Color second: S. viridis has blue centers with orange or reddish segment margins and orange-yellow legs; H. marginata is olive to blue-grey overall with a dark or blue margin on each segment and blue “tick” marks on the legs. Leg count does not separate them — both have 21 pairs of legs — so use size and color, not a leg count. The look-alikes section below walks through the full check, and the Eastern Bark Centipede guide covers the other Florida blue in full.

The taxonomy, for the nerds in the back: kingdom Animalia, phylum Arthropoda, class Chilopoda (the centipedes), order Scolopendromorpha, family Scolopendridae, genus Scolopendra. The Scolopendromorpha are the big, tropical-to-subtropical centipedes — the bark centipedes — and Scolopendra is their biggest genus. S. viridis was described by Thomas Say in 1821, the same year he described its eastern cousin H. marginata — two species, one year, one shared nickname, and two centuries of confusion ever since.

One more honest complication, and it is a big one. A 2018 venom study compared Florida S. viridis with S. viridis from Morelos, Mexico, and found only five venom toxins in common out of 39 confirmed in the Florida animals — so little overlap that the researchers raised the possibility that the two populations are entirely different species. The name S. viridis may currently cover more than one real species. This guide treats the Florida and southeastern animal as S. viridis in the usual sense, and it says so plainly, because pretending the taxonomy is settled would be dishonest — and because a gardener in Florida is meeting the Florida animal either way.

Range: the Southeast — and further west than you would think

Here is the range, stated plainly. The Florida blue centipede occurs throughout Florida — all of the state, according to the distribution maps compiled by R. M. Shelley, the authority on North American centipedes — and across the southeastern United States, from the sandhills and coastal islands of North Carolina south through the peninsula and west to Louisiana. It also occurs in Mexico, Central America, and the southwestern United States. Shelley’s range map runs it west as far as Kansas, Utah, and Nevada, in scattered records — further west than most field guides suggest, and a reminder that a species’ range on paper is always a little larger than its range in the popular imagination.

Within Florida it is a creature of damp, dark places: under the bark of fallen oaks — the exact spot UF/IFAS’s classroom arthropod guide names — under logs and stones, in leaf litter, in rotting wood, and in the soil under potted plants. It is also a burrower: laboratory studies of its burrowing found that it produces dense networks of vertical and horizontal burrows, wedging its body through the sediment and compacting it sideways, spending a large part of its life below the surface. That is why you meet it when you lift a log or roll a stone, and almost never out in the open in the middle of the day. It is fast, it runs when disturbed, and it is gone under the next log before you have finished the sentence.

It is worth saying plainly what this range means for the rest of the library: this is the large centipede of the Florida garden. The Garden Centipedes guide already covers it in brief, alongside the house centipede, the soil centipedes, and the stone centipedes — this is its species guide now, the full version of that sketch.

What it eats: the night hunter of the leaf litter

The Florida blue centipede is a predator, and an aggressive one. Its diet is insects, spiders, other centipedes, earthworms, and small soil animals — anything it can catch and overpower in the leaf litter and the soil. It hunts mainly at night, using its antennae to feel and smell its way along the ground and through its burrows, and it strikes fast: it grabs prey with its front legs, drives the forcipules in, injects venom, and holds on while the venom works. The venom is a mix of dozens of toxins — the 2018 study confirmed 39 in the Florida animals alone — that paralyze prey and begin breaking down tissue, and it is fast-acting on small animals. The centipede then eats its prey in pieces, using its mouthparts to tear off manageable chunks.

What it does not like is just as useful to know. It does not like heat and dry air: like all centipedes, it loses water through its cuticle and dries out fast in open, sunny conditions, so it hunts at night and shelters under cover by day — under bark, in burrows, inside rotting logs. It does not like being exposed — it is a target for birds and other predators, and its first response to disturbance is usually to run for cover, fast. And it does not eat plants, dead or alive: it has no interest in your garden beds as food. It is interested in your garden beds as hunting ground, because that is where the insects and the earthworms are.

The bite: honest, plain, and not sensational

Let us be direct, because this is the section people actually need. The Florida blue centipede can deliver a painful bite. It punctures the skin with its two forcipules, leaving two small puncture marks, and injects venom. The pain is immediate, sharp, and stinging — often compared to a bee sting — with redness, swelling, and tenderness around the bite. UF/IFAS’s guidance on Florida centipedes is that the larger species are capable of painful bites and should not be handled, and that is the whole rule: do not handle it, and it will not bite you.

That is the honest scale of it: a painful bite, not a dangerous one for most people. The National Capital Poison Center’s guidance for centipede bites in general is that symptoms most often last less than 48 hours, and Clemson Cooperative Extension states flatly that bites from U.S. centipedes are not toxic enough to be deadly to adults or children. But “not deadly” is not “harmless,” and allergic reactions to centipede venom are possible — which is why the first-aid section below includes the emergency signs. A bite from this species is also, in the honest accounting, a bite you almost certainly earned by picking the animal up or trapping it against your skin: it does not go looking for people to bite.

If you are bitten: what to do

This is first-aid guidance from MedlinePlus (U.S. National Library of Medicine) and the National Capital Poison Center, not folk wisdom. Wash the bite with soap and water right away. Place ice wrapped in a clean cloth on the bite for 10 minutes, then off for 10 minutes, and repeat. Take an over-the-counter pain reliever such as acetaminophen or ibuprofen for the pain. Centipede venoms are sensitive to heat, so soaking the area in warm water may also help reduce pain and swelling. Make sure your tetanus shot is current — a centipede bite is a puncture wound, and the Poison Center specifically advises checking that you have had a tetanus shot in the previous 10 years.

Call Poison Control at 1-800-222-1222 — free, private, available 24 hours a day — if you have any questions at all about a bite; MedlinePlus says to contact poison control just to be sure, even if the bite seems mild. Seek medical care promptly if the swelling or pain keeps getting worse instead of better, if redness spreads, if you develop fever or pus at the site, or if the bite is on a child, an older adult, or someone with a health condition. Call 911 immediately — do not drive yourself — if there is trouble breathing, swelling of the lips, tongue, mouth, or throat, widespread hives, dizziness, confusion, or fainting. Those are signs of a serious allergic reaction, which can happen with any venomous bite or sting even in someone with no known allergy, and they need emergency treatment. If the person has a prescribed epinephrine auto-injector, use it according to their emergency plan and then call 911.

What not to do: do not apply a tourniquet, do not try to suck out the venom, do not cut the wound, and do not apply alcohol or home remedies to the puncture. Soap, water, ice, pain relief, and a phone call are the whole list, and they are enough for the great majority of bites.

Life cycle: born small, guarded by its mother

Like other Scolopendra species, the Florida blue centipede reproduces by laying eggs, and the female guards them. She lays a clutch in a sheltered underground chamber or under bark, then coils her body around the eggs and stays with them, cleaning them and defending them until they hatch — weeks of maternal care that is unusual among arthropods and one of the more likeable facts about an otherwise intimidating animal. The hatchlings start small, with fewer segments and legs than an adult, and earn the rest by molting: shedding the exoskeleton, adding segments and leg pairs, and hardening up again, bigger than before.

The details beyond that — exactly how long it lives in the wild, how many eggs a female lays, how many years it takes to reach full size — are thinly studied for this species specifically, and this guide will not invent them. Trade sources describe it as relatively short-lived for a large centipede, around a year and a half to two years, but that figure comes from the pet trade, not from field research, and this guide reports it as a trade figure, not a fact. What is certain is the rhythm: warm-season activity for most of the year in Florida, with the most encounters on warm, humid nights, and a retreat deep underground and under bark during cold snaps and dry spells.

The Florida angle: the big centipede in your own yard

Here is the honest Florida story. The Florida blue centipede is a native, not an invader — it belongs here, in the hammocks, the flatwoods, and the gardens, in a way the house centipede never will. And unlike the rare animals in this library, it is one a Florida gardener can actually meet: under the bark of a fallen oak, under a log at the edge of the garden, under a stone in a damp corner, in the soil of a potted plant left on the ground. It is most often found in South Florida — Palm Beach, Miami, Orlando — and in the Apalachicola National Forest in the Panhandle, but the range maps run it through the whole state, and any damp, wooded, log-strewn corner of a Florida yard is fair game.

That ordinariness is the point: this is not a rare animal to protect or a pest to exterminate. It is a working part of the garden’s underground economy, a predator that eats the insects and the earthworms and the other small animals of the leaf litter, and it has been doing that job in Florida far longer than there have been gardens here. Finding one in your yard is not a problem to solve. It is a sign that your leaf litter has a food web in it. Leave the log alone, and it will get on with the job.

Is it a pest?

Plainly: it is not a plant pest, but it is not an animal to welcome into your living room either. It does not eat plants, does not damage structures, does not eat stored food, and does not spread disease. What it does is hunt — and the things it hunts are mostly things gardeners want gone. A Florida blue centipede in the yard is a sign that your garden has a healthy population of insects, spiders, and other small animals for it to eat, and it is doing free pest control at a scale few other invertebrates in Florida can match.

Against that, weigh the bite. This is a large centipede with a painful bite, and it is a genuine reason to keep it out of the house and away from small children and pets. The goal is not to exterminate it from your property — it is a native predator doing a native job, and killing every one you see will not reduce the population, because more will move in from the surrounding leaf litter. The goal is separation: let it hunt outside, keep it outside, and give it no reason to come in.

Effects on the garden

On the plus side, the Florida blue centipede is a serious predator of garden pests. It eats cockroaches, crickets, spiders, and other centipedes, and it hunts the ground layer — under logs, along walls, through the mulch, and down into the soil through its burrows — that most other predators do not patrol at night. In a Florida garden, where the pest pressure comes from the ground up and the nights are warm all year, that is a genuinely useful service.

On the minus side, it is indiscriminate. It eats beneficial insects and spiders as readily as pests, and it eats earthworms — the animals this whole site is built around — as readily as it eats cockroaches. That is the honest trade-off, and it is worth stating plainly on a site that loves earthworms: the Florida blue centipede eats earthworms. It does not eat plants, so there is no direct crop damage to warn about, and its burrowing is shallow and does not disturb roots the way a burrowing mammal does. The honest accounting is that it is a net wash for the garden as a whole — a powerful predator that removes pests and beneficials alike, including some of the good guys — and the decision about whether to tolerate it should turn on safety, not on garden economics. In a yard where children and pets play barefoot, the safety answer wins, and the centipede should be kept out of the play area. In a damp back corner nobody walks through, leaving it alone is the better call.

Effects on other garden animals

The Florida blue centipede sits near the top of the invertebrate food web in its range, and it pulls hard in both directions. As a predator it eats insects, spiders, other centipedes, earthworms, nematodes, and small soil animals — anything it can catch and hold in the leaf litter and the soil. Its competition is with other nocturnal predators: night snakes, owls, and larger lizards all hunt the same ground, and in a rich yard there is usually enough prey for all of them. It does not compete with millipedes for food, because it does not eat dead plant matter — but it does eat millipedes themselves, occasionally, if it catches one out in the open.

As prey, it is a defended meal. Its speed, armor, and venom put off most predators, but it is still eaten: birds, raccoons, opossums, and some snakes all take large centipedes. For pets, the risk is real and worth stating plainly: a dog or cat that grabs a Florida blue centipede is likely to be bitten on the mouth, and the bite is painful enough to cause swelling, drooling, pawing at the face, and distress. It is rarely life-threatening to a healthy adult pet, but a small dog, a cat, or a pet that is bitten repeatedly should be seen by a veterinarian promptly. Keep pets from investigating one, and if your pet does get bitten, watch for swelling of the face or mouth, difficulty breathing, or vomiting, and call your vet.

Look-alikes: the concrete checks

Large centipedes all look alike until you know what to check, and the checks are wonderfully simple — size, color, leg count, and where you are. Work through them in order and you will rarely go wrong. The hard one in this guide is the first cousin, so start there.

Eastern Bark Centipede (Hemiscolopendra marginata) — the other Florida blue, and the hardest check in Florida. The two share the name “Florida blue centipede,” they share the state, and they share the leaf litter — and half the photos labeled “Florida blue” online are this one. Check the size first: S. viridis is 3 to 4 inches and up, with large adults to about five and a half inches; H. marginata tops out around 3 inches. Check the color: S. viridis has blue centers with orange or reddish segment margins and orange-yellow legs; H. marginata is olive to blue-grey overall with a dark or blue margin on each segment and blue “tick” marks on the legs. Leg count does not separate them — both have 21 pairs of legs — so size and color do the work. Read the full guide: Eastern Bark Centipede.

Giant Red-Headed Centipede (Scolopendra heros) — the bigger cousin you will not meet in Florida. The giant red-headed is 6.5 to 8 inches, red-headed with a black body and yellow legs, and it is the largest centipede in North America. Check: six inches or more and a red head means giant red-headed; three to four inches and blue-centered segments means Florida blue. Check the range: the giant red-headed does not occur in Florida at all — its eastern limit is Arkansas and Louisiana. If it is huge and you are in Florida, it is not heros. Read the full guide: Giant Red-Headed Centipede.

Common Desert Centipede (Scolopendra polymorpha) — the southwestern cousin. The desert centipede is 4 to 7 inches, tan to orange with one dark tiger stripe down each segment, and it lives in the deserts of the Southwest. Check: tiger striping and four to seven inches means desert centipede; blue-centered segments and three to four inches means Florida blue. Check the range: the two barely overlap, and in Florida itself the desert centipede does not occur at all. Read the full guide: Common Desert Centipede.

Florida Keys giant centipede (Scolopendra alternans) — the one that is bigger in the wrong place. This Caribbean species occurs in the Florida Keys and the far southern tip of Florida, and very large adults can reach 7 to 10 inches — far bigger than a Florida blue. Check the range: it is restricted to the Keys and extreme south Florida. Check the size: anything over five inches in the Keys is alternans, not viridis. If it is huge and you are in Key West, it is alternans; if it is three to four inches and you are anywhere in Florida, it is viridis. No guide yet — its story is still to come in this library.

Eastern red centipede (Scolopocryptops sexspinosus) — the other red one, and the one with no guide in this library yet. This is the animal most field guides actually call the eastern red centipede: bright red to orange-red, up to about 2.7 inches, fast, and common across the eastern United States including Florida. It is smaller than a Florida blue, it has 23 pairs of legs, and it has no eyes. If it is red, eastern, and under three inches, it is one of the eastern red centipedes, not a Florida blue. No link yet — its guide is still to come.

Florida Ivory Millipede (Chicobolus spinigerus) — the millipede that shares the leaf litter. The Florida ivory is a large native millipede, black on top and pale ivory underneath, up to three and a half inches — and it lives under the same logs as the Florida blue. Check: two pairs of legs per segment, slow movement, and curling up when disturbed means millipede; one pair of legs per segment, fast movement, and running when disturbed means centipede. The millipede cannot bite at all. Read the full guide: Florida Ivory Millipede.

Millipedes in general — the ones that look similar and are not centipedes at all. A large millipede can alarm a gardener the same way, but millipedes have two pairs of legs per segment, move slowly, curl up when disturbed, and cannot bite. Centipedes have one pair of legs per segment, move fast, and run when disturbed. Check: count the legs per segment, then watch the speed. If it curls, it is a millipede. If it darts, it is a centipede. Read the full guide: Garden Centipedes.

How to keep it out (not how to attract it)

This is a helper outdoors and a hazard indoors, so the question is not how to attract it — it is how to keep the separation. The Florida blue centipede needs exactly three things, and all three are things you can manage at the edges of your property:

Seal the house at ground level. Door sweeps, weatherstripping, and caulk around windows, pipes, and foundation gaps, looking low, where the wall meets the ground. A centipede needs a gap, not a door — but a gap under a garage door or around a pipe is enough. Keep the gaps closed and the animal stays outside, where it belongs.

Clear the cover next to the house. Flat stones, boards, firewood piles, and dense mulch stacked against the foundation are centipede hotels, and they are also cockroach and cricket hotels — which is what the centipede is hunting. Move firewood away from the wall, keep mulch a few inches back from the foundation, and clear rock and log piles from the immediate perimeter. You do not need to clear your whole yard. You need to clear the ten feet around the house.

Reduce the prey at the door. Outdoor lights attract the insects that attract the centipedes, so consider motion-sensor lights or yellow “bug” bulbs near entrances instead of white lights left on all night. Fix dripping outdoor faucets and standing water, which draw the insects and the centipedes both. A yard with fewer insects at the foundation has fewer centipedes at the foundation.

Do not spray the yard for it. Broad insecticide sprays do not distinguish between a pest and a predator, and a sprayed yard is a dead yard — the centipede will die, and so will the spiders, the ground beetles, and the other hunters that were keeping the actual pests down. If one is inside, the fix is a long pair of tongs or a large jar with a lid, used from arm’s length, tipped outside far from the house — or a call to a pest professional who will relocate it. Never use bare hands.

If you want it in the yard, leave the back corners alone. A damp, log-strewn back corner away from the house is exactly the habitat this animal wants, and a resident centipede there will hunt cockroaches all night for free. The deal is simple: it gets the back corner, you get the house. That is the whole arrangement, and it works.

Frequently asked questions

Is the Florida blue centipede dangerous?
Its bite is painful — a sharp sting with redness and swelling, often compared to a bee sting — but it is not considered life-threatening to a healthy adult. UF/IFAS’s guidance is that the larger Florida centipedes are capable of painful bites and should not be handled. Children, older adults, and anyone with an insect-venom allergy should take a bite more seriously, and anyone with difficulty breathing after a bite needs emergency care immediately. Do not handle it.

Does it bite?
Yes. It has a pair of venom fangs called forcipules and will bite if handled, cornered, or stepped on. It does not go looking for people to bite — bites happen when a person picks one up, rolls onto one, or puts on a shoe it is hiding in. Shake out shoes and clothing left on the floor.

How big does it get?
Adults are typically 3 to 4 inches (75 to 100 mm) long, with 21 pairs of legs, and large adults can reach about five and a half inches — one Florida specimen measured for a venom study was 13.8 centimeters.

Why are there two Florida blue centipedes?
Because the common name is used for two different species: this one, Scolopendra viridis, and the smaller eastern bark centipede Hemiscolopendra marginata. Size is the quickest check — viridis is 3 to 4 inches and up, marginata tops out around 3 inches — and color is the second: blue centers with orange margins means viridis; olive to blue-grey with blue tick marks on the legs means marginata.

Is it the only big centipede in Florida?
No. Florida also has the other Florida blue (Hemiscolopendra marginata), the eastern bark centipede (Scolopocryptops sexspinosus), the Florida Keys giant centipede (Scolopendra alternans) in the Keys, and the house centipede indoors. This one is the large Scolopendra a Florida gardener is most likely to meet under a log.

What does it eat?
Insects, spiders, other centipedes, earthworms, and small soil animals. It is a nocturnal predator that hunts live prey in the leaf litter and the soil and subdues it with venom. It does not eat plants — but it does eat earthworms, which is worth knowing on a site that loves them.

Will it hurt my plants?
No. It eats no plant matter at all. It hunts in garden beds because that is where the insects and the earthworms are, not because it wants your plants. It is a predator, not a pest, as far as your plants are concerned.

Will it hurt my dog or cat?
A pet that grabs one is likely to be bitten on the mouth, which is painful and can cause swelling, drooling, and distress. It is rarely life-threatening to a healthy adult pet, but a small pet, or one bitten repeatedly, should be seen by a veterinarian promptly. Watch for swelling of the face or mouth, difficulty breathing, or vomiting, and call your vet.

What should I do if I am bitten?
Wash with soap and water, apply ice wrapped in a cloth for 10 minutes on and 10 minutes off, and take an over-the-counter pain reliever. Make sure your tetanus shot is current. Call Poison Control at 1-800-222-1222 with any questions. Seek medical care if swelling or pain keeps getting worse, or if there are signs of infection. Call 911 immediately for trouble breathing, throat or mouth swelling, widespread hives, or fainting.

Should I kill it if I find one in my yard?
No — not as a rule. Outdoors, away from the house, it is a native predator doing free pest control, and killing it will not reduce the population, because more will move in from surrounding leaf litter. Keep it out of the house, keep it out of the play area, and let it hunt the back corners. If one is inside, relocate it with long tongs or call a professional. Never handle it with bare hands.

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🌱 Keep learning

Three related guides worth reading next:

• Eastern Bark Centipede — The other Florida blue: the smaller bark centipede that shares the nickname, the leaf litter, and the state — and how to tell the two apart.
• Giant Red-Headed Centipede — The bigger cousin: eight inches of red head and black body, the largest centipede in North America, and the one that does not live in Florida at all.
• Garden Centipedes — The whole family at a glance: house centipedes, soil centipedes, stone centipedes, and the one leg-count check that separates them all from millipedes.