Bark Scorpions: Arizona vs Striped, Stings and Where They Live
The Arizona bark scorpion, Centruroides sculpturatus, is the only US scorpion whose sting is a medical concern, while its cousin the striped bark scorpion, C. vittatus, of Texas and the southern plains, is painful but rarely serious. Most healthy adults stung by an Arizona bark scorpion recover within a day or two, and deaths are extremely rare. Severe stings are concentrated in children under 10 in Arizona and Nevada, an antivenom exists, and pets usually suffer local pain rather than systemic poisoning.
“Bark scorpion” covers two animals with different risk profiles. Here is how to tell them apart, where each lives, what poison centre data says about who gets hurt, and the exclusion steps extension entomologists recommend over spraying.
Arizona bark scorpion vs striped bark scorpion at a glance
| Arizona bark scorpion | Striped bark scorpion | |
|---|---|---|
| Scientific name | Centruroides sculpturatus | Centruroides vittatus |
| Adult length | 2 to 3 in (about 51 to 76 mm) including tail | About 2.5 in (about 64 mm) |
| Colour | Light tan to yellow brown; some darker, striped or checkered | Yellowish tan with two broad dark stripes and a dark triangle on the head |
| Build | Slender pincers, long slender tail | Slender pincers, long slender tail, longer in males |
| Core range | Arizona, plus small parts of CA, NV, NM, UT, CO, TX | Texas statewide, Oklahoma, Kansas, Missouri, Arkansas, Louisiana, New Mexico, Colorado |
| Climbs walls | Yes, strongly; the only climbing scorpion in Arizona | Yes; often found in attics |
| Sting | Neurotoxic; numbness, tingling, rarely swelling; can be severe in small children | Painful; Texas A&M says only moderate reactions in most people |
| Life span | About 5 to 7 years | About 4 years |
| Young per brood | Usually 25 to 35 | 13 to 47, average 31 |
The most useful fact in that table is geographic. In east Texas, Oklahoma or Missouri, the scorpion on your wall is almost certainly the striped bark scorpion, whose sting the Missouri Department of Conservation calls quite painful but almost never life threatening. In the low desert of Arizona or around Las Vegas, assume Arizona bark scorpion.
How to identify a bark scorpion
Both species share the Centruroides build: a flattened body, four pairs of legs, thin pincer arms and a long, thin tail. That slenderness is the field mark. The University of Arizona notes that the stripe-tailed scorpion and yellow ground scorpion, which are often mistaken for bark scorpions, are burrowers with bulkier pincers or noticeably wider tails, and their venom is relatively mild.
Colour alone will not settle it. Arizona extension publication AZ1768 says Arizona bark scorpion colouring is highly variable, “some being pale in color, others darker with stripes or checkered patterning.” Stripes therefore do not prove you have a striped bark scorpion. Range does most of the work, and behaviour does the rest: in Arizona, a scorpion on a vertical wall or ceiling is a bark scorpion, because it is the only species there with the ability and strong tendency to climb.
Striped bark scorpions are not always striped either: Texas A&M says Big Bend populations may be faint or pale, and Missouri notes older adults can turn uniform dark brown.
How large can bark scorpions be in Arizona?
The University of Arizona gives adults as 2 to 3 inches (about 51 to 76 mm), tail included, with males slightly larger than females; the full range from newborn to adult runs from about a quarter inch to 3 inches. Grand Canyon National Park gives a maximum of about 2.5 inches (6.4 cm). Some online summaries quote 8 cm for males, which is longer than either primary source. The scorpion you see that is well over 3 inches and heavy bodied is more likely the Arizona giant hairy scorpion, which often exceeds 5 inches, has mild venom and, as UA puts it, eats bark scorpions “voraciously.”
Where bark scorpions live
AZ1768 places the Arizona bark scorpion across the low desert southwest, colonising small parts of California, Nevada, New Mexico, Utah, Colorado, Texas and northwestern Mexico. The striped bark scorpion is, in Missouri’s words, the most common and widely distributed scorpion in the United States, and Texas A&M says it is the only one of Texas’s 18 species found throughout the state.
Our analysis of iNaturalist records shows the two ranges barely overlap: Arizona bark scorpions in Arizona, Nevada and Utah, striped bark scorpions from Texas to Missouri, and both in New Mexico.
For the striped bark scorpion alongside Texas’s other household pests, see common house bugs in Texas.
When bark scorpions are active
Both are night hunters of crickets, cockroaches and other insects. Sources give slightly different temperature triggers for the Arizona species: AZ1768 says nighttime temperatures above 70°F are ideal, Grand Canyon National Park says they overwinter until evenings stay above 73°F, and a University of Arizona Backyard Gardener column puts activity at night lows above about 77°F. Read those as a range: once nights stay in the 70s, expect activity. From roughly November to March they cluster in sheltered groups, which is why winter remodelling can turn up dozens in a block wall.
Poison centre data analysed by Kang and Brooks (2017) showed a sustained June to September plateau of stings in Arizona and Nevada, while Texas peaked in May and June and Oklahoma in July and August. Stings cluster in the evening, peaking between 9 and 11 pm nationally. Insects are also more active at night, as our explainer on why bugs come out at night covers, and a yard full of crickets is a yard full of scorpion food; see what attracts crickets.
Climbing, hiding and the UV glow
Bark scorpions are crevice dwellers. In research summarised by UA, 95 per cent of Arizona bark scorpions chose hollow block walls over every other refuge on offer around buildings. They climb textured walls, cross ceilings and can drop into beds, sinks and bathtubs, but cannot grip the most slippery surfaces, such as glass. UA also warns that a scorpion in a pool may still be alive and able to sting.
Like other scorpions they glow under ultraviolet light: Grand Canyon rangers describe a bright bluish glow and UA describes bright green. UA’s practical advice is to search with a UV light after dark, between about 8 and 11 pm, three or four times a summer, wearing boots and using long tongs; repeated collections can greatly decrease a local population.
Are bark scorpions dangerous?
Only the Arizona bark scorpion, per AZ1768. Its sting causes immediate burning pain followed, in some people, by numbness, tingling and nerve effects. National poison centre data show how different it is from other species.
| State | Average stings reported per year | Numbness | Local swelling | Major effects |
|---|---|---|---|---|
| Arizona | 11,500 | 83.9% | 0.9% | 0.20% |
| Texas | 1,743 | 6.7% | 11.9% | 0.02% |
| Nevada | 707 | 14.9% | 9.0% | 0.13% |
| Florida | 567 | 2.1% | 13.0% | 0.03% |
| California | 498 | 3.4% | 5.5% | none reported |
| Georgia | 447 | 1.3% | 14.0% | none reported |
| Oklahoma | 301 | 4.9% | 14.1% | none reported |
| New Mexico | 298 | 13.4% | 19.4% | 0.03% |
| Alabama | 194 | 1.7% | 19.5% | 0.05% |
Compiled by The Pest Control Brief from Kang and Brooks, Journal of Medical Toxicology 2017, National Poison Data System 2005 to 2015. Percentages are shares of each state’s reported exposures.
The swelling column is the surprise. Arizona stings almost never swell (0.9 per cent), while swelling and redness are far more common elsewhere. The authors call this typical of C. sculpturatus: numbness and tingling with little to see is the classic picture. Our bite identification guide covers other stings and bites that get confused with it.
How bad is bark scorpion venom?
Serious in small children, usually manageable in healthy adults. AZ1768 says symptoms generally develop within 20 minutes and can worsen over the first four hours. Untreated, most healthy adults recover within a day or two, though pain, numbness and tingling can persist for several days. Clinicians grade envenomation on a four point scale:
| Grade | What clinicians look for | Severity |
|---|---|---|
| 1 | Pain or burning, prickling at the sting site | Mild |
| 2 | Pain or prickling spreading away from the sting site | Mild |
| 3 | Cranial nerve signs (roving eye movements, tongue twitching, drooling, slurred speech) or jerking of the arms and legs | Severe |
| 4 | Both cranial nerve and neuromuscular signs | Severe |
Age drives risk. UA singles out children under 9 or under 70 lb (32 kg), the elderly and people with high blood pressure. In the national data, children under 10 accounted for two thirds of all major effects, and their hospitalisation rate was about seven times that of adults in their 20s to 40s.
Can a bark scorpion kill you?
It can, but it almost never does in the US today. Kang and Brooks found 276 major effects among 185,402 scorpion exposures over 11 years, and only one recorded death in that data set, in Arizona in 2013. CDC mortality records list seven US deaths from contact with scorpions between 1999 and 2014. The researchers also found that Arizona ICU admissions for scorpion stings fell from 111 in 2005 to 16 in 2015, a drop that started in 2007, the year the clinical trial of today’s antivenom began.
What do you do if you get stung by a bark scorpion?
Call Poison Help on 1-800-222-1222, a free, confidential line answered 24 hours a day. For a child aged 9 or under or weighing under 70 lb, the University of Arizona says to call 911 or Poison Help, or take the child to the nearest hospital, immediately, and to treat stings in people with high blood pressure as serious too. Difficulty swallowing, frothing at the mouth and breathing trouble are the warning signs it highlights. Poison specialists then advise whether the sting can be managed at home; AZ1768 says about 90 per cent of calls to the Arizona Poison and Drug Information Center are handled at home.
Antivenom, and what bark scorpion venom is worth
The US antivenom is Anascorp, Centruroides (Scorpion) Immune F(ab’)2 (Equine), licensed by the FDA in 2011 “for the treatment of clinical signs of scorpion envenomation.” Texas A&M notes it is made from the plasma of horses immunised with scorpion venom. In the trial behind it, published in the New England Journal of Medicine in 2009, symptoms resolved within four hours in all eight critically ill children given antivenom against one of seven given placebo. It is stocked at selected hospitals for severe cases.
How much is bark scorpion venom worth?
We could not find any primary source that puts a market price on bark scorpion venom, and the dramatic per gallon figures that circulate online do not trace back to one. Its real value is as the raw material for research and for immunising the horses used to make antivenom.
Can a bark scorpion kill a dog or cat?
Rarely. The Merck Veterinary Manual says US scorpions are unlikely to cause envenomation in companion animals, and in most dogs an Arizona bark scorpion sting stays local: pawing, limping, crying out, swelling and itch. Systemic signs are not common, the most frequent being a fast heart rate and high blood pressure, with agitation, twitching and drooling also possible. UA adds a warning for cat owners: cats are not immune, may play with scorpions and can withstand a number of stings before succumbing. If a pet is stung, call your vet; our guide to pest control that is safe around pets and children covers treatment choices for the home.
Keeping bark scorpions out
Both UA and Texas A&M state plainly that scorpions are difficult to manage with insecticides alone. UA goes further: eliminating them from a landscape would take “extremely unhealthy and illegal chemical use.” Exclusion and habitat changes come first.
- Fit door sweeps and weather stripping on every exterior door, a main entry route.
- Screen weep holes with coarse steel mesh. UA warns not to seal them shut because they ventilate wall spaces; Texas A&M suggests plugging them with steel wool, copper mesh or screen squares, noting steel wool rusts on light facades.
- Caulk around eaves, pipes and wall penetrations, and keep window screens tight.
- Stucco and cap hollow block walls, the refuge bark scorpions prefer above all others.
- Prune branches off the roof and keep low ground cover, rocks, boards and woodpiles away from the house.
- Change habits indoors: no shoes or towels left on the floor, shake out shoes and clothes, and burn firewood straight from outdoors.
- Collect with a UV light on summer evenings, as above.
Our step by step guide to pest proofing your home covers the sealing work in more detail. UA advises calling a pest management professional experienced with scorpions if you regularly find them indoors, and many offer sealing as a service; our breakdown of scorpion control cost explains why sealing usually pays back better than monthly spraying. Any product used should be applied exactly as the label directs.
Frequently asked questions
Is the striped bark scorpion dangerous?
Usually not. Texas A&M says stings from Texas scorpions produce only moderate reactions in most people because the venom has little effect on the nervous system. National poison centre data recorded just four major effects among 19,168 Texas exposures over 11 years. As with bee stings, an allergic reaction is possible, and breathing difficulty or swelling that persists needs immediate medical attention.
Can bark scorpions climb glass?
Not well. The University of Arizona says Arizona bark scorpions climb and hang upside down on all but the most slippery surfaces, giving glass as the example. That is why they get stuck in sinks and bathtubs and why a smooth sided bucket works for UV collections.
Do bark scorpion stings swell?
Arizona bark scorpion stings rarely do. In national poison centre data, local swelling was reported in only 0.9 per cent of Arizona exposures, against 11.9 per cent in Texas and up to 19.5 per cent in Alabama. The typical Arizona picture is burning pain with numbness and tingling and little to see at the site, which is one reason the sting can be underestimated.
How long do bark scorpions live?
The University of Arizona and Grand Canyon National Park both give five to seven years for the Arizona bark scorpion. Texas A&M gives about four years for the striped bark scorpion, which reaches maturity in a year or so after five or six molts. Young ride on the mother’s back for one to three weeks before dispersing, so a single female can seed a block wall for years.
Sources
- Gouge, Li, Bibbs and Nair, Scorpions of the Desert Southwest United States, University of Arizona Cooperative Extension AZ1768, 2018.
- Gouge, Li, Bibbs and Nair, Living with and Managing Scorpions, University of Arizona Home and School IPM Newsletter, 2022.
- University of Arizona Cooperative Extension, Yavapai County, Backyard Gardener #184: Scorpions, 2024.
- Brown, Scorpions, Texas A&M AgriLife Extension ENTO-PU-032, 2022.
- Texas A&M AgriLife Extension, Insects in the City: First scorpion sting antidote, 2012.
- Missouri Department of Conservation, Field Guide: Striped Bark Scorpion.
- National Park Service, Grand Canyon National Park: Bark Scorpion, 2025.
- Kang and Brooks, Nationwide Scorpion Exposures Reported to US Poison Control Centers from 2005 to 2015, Journal of Medical Toxicology 13(2), 2017.
- Arizona Poison and Drug Information Center, 2025 Annual Report.
- Klotz and others, Scorpion stings and antivenom use in Arizona, American Journal of Medicine, 2021.
- Boyer and others, Antivenom for Critically Ill Children with Neurotoxicity from Scorpion Stings, New England Journal of Medicine 360, 2009.
- US Food and Drug Administration, Anascorp product page and approval history documents.
- Merck Veterinary Manual, Spider and Scorpion Bites and Stings to Animals, 2026.
- The Pest Control Brief analysis of iNaturalist research-grade records, pulled October 2026.
