Arizona Bark Scorpions

Centruroides sculpturatus is the name the current publications use. University of Arizona Cooperative Extension states plainly what separates it from every other scorpion a reader in the desert southwest is likely to meet: “The Arizona bark scorpion is the only scorpion of medical concern in the U.S. (Curry et al. 1983), and while all native scorpions can sting, only Arizona bark scorpion stings are hazardous to human health.”

Because that is the whole difference, the identification section comes first and the sting section comes second, before anything else on this page. Everything below is drawn from university extension services, one FDA register entry and one peer-reviewed paper, each named in the sentence that uses it and listed at the foot of the page.

Which Scorpion Is It

The character that needs no magnification, and no scorpion in your hand, is climbing. University of Arizona Cooperative Extension states that bark scorpions “are the only scorpion in Arizona with the ability and strong tendency to climb – a characteristic which can aid in a quick identification.” Texas A&M AgriLife Extension gives a second character visible at a distance: “Centruroides bark scorpions are relatively easy to identify by the way they hold their tails when at rest. They tend to hold their tails curled to the side, rather than upright over the body like most other scorpions.”

On size and colour, University of Arizona Cooperative Extension states: “Adults are 2-3 inches in length, have relatively slender appendages and a long, slender tail. Their coloration and markings are highly variable, some being pale in color, others darker with stripes or checkered patterning.” Colour is therefore not a diagnostic character, and the same publication elsewhere gives the range as 0.25 to 3 inches for the animals encountered in and around houses.

The close-up characters are set out in the University of Arizona pest-proofing publication: the slender pincers, “the presence of a tooth or tubercle at the base of the stinger”, and a long triangular sternum where all other Arizona species have a five-sided or pentagonal one. That publication also states that these features may require magnification to be observed clearly, which is worth knowing before anyone leans in to look.

The two most common look-alikes are not the dangerous one. Of the Arizona giant hairy scorpion Hadrurus arizonensis, University of Arizona Cooperative Extension states that it is “the largest scorpion in the U.S.”, that adults “often exceed 5 inches in length”, and that they have “a mild venom”. It then says something a reader about to step on one should probably know: “These harmless giants spend most of their time under rocks and in shallow burrows; they are a beneficial addition to your home landscape as they consume Arizona bark scorpions voraciously.”

Of the Arizona stripe-tailed scorpion Paravaejovis spinigerus and the yellow ground scorpion Vaejovis confusus, the same publication states they are “often mistaken for bark scorpions, but the stripe-tailed scorpion is heavily armored, with comparatively bulkier pedipalps and tail”, and that their venom “is relatively mild, and does not usually require medical intervention.”

A note on the scientific name. The current University of Arizona, Texas A&M and peer-reviewed publications all use Centruroides sculpturatus. UC IPM, whose Pest Note was last updated in December 2011, uses the reverse convention and writes of “the bark scorpion, Centruroides exilicauda (formerly C. sculpturatus)”. Both names refer to the animal described here.

The Sting

Everything in this section is what a named publication says. This site is not a medical source and does not assess anyone’s symptoms. University of Arizona Cooperative Extension states: “The Arizona bark scorpion is the only scorpion species of medical significance in the United States. However, a sting is not likely to be fatal, or cause long-term injury as long as medical treatment for infants and children is immediately acquired.”

For adults the same publication is less alarming and still points at the same phone number: “Most healthy adults can manage a sting without seeking the help of a doctor, but it is always advisable to call the Poison Help Hotline 1 (800) 222-1222 for advice, as each individual has a unique response.” It also reports how those calls usually end: “Approximately 90% of scorpion sting exposures reported to the Arizona Poison and Drug Information Center via the Poison Help Hotline are treated at home, reducing the costs of unnecessary medical care.”

The first aid, as published. University of Arizona Cooperative Extension sets out what it describes as the first aid recommended by the Poison Help Hotline. It is four steps and this is all of them: call the Hotline at 1 (800) 222-1222 immediately, where a certified specialist will review the symptoms and provide treatment advice or recommend transport to the emergency room if necessary; “Wash the area with soap and water.”; “Apply a cool compress on the area of the scorpion sting for ten minutes. Remove compress for ten minutes and repeat as necessary.”; and “If stung on an arm or leg, rest the affected limb in a supportive position.” Nothing is added to that list here. UC IPM gives one instruction the Arizona publication does not: “Keep the sting victim calm and relaxed, and don’t allow the consumption of alcohol or other sedatives.”

What the sources say the symptoms are, and where they disagree. University of Arizona Cooperative Extension states that the venom “may produce severe pain (but rarely swelling) at the site of the sting, numbness, frothing at the mouth, difficulties in breathing (including respiratory paralysis), muscle twitching, flailing limbs, and convulsions.” UC IPM describes the same sting differently, stating that “the bark scorpion’s sting can be serious, causing severe pain and swelling, respiratory paralysis, and convulsions.” One says swelling is rare and the other lists swelling among the effects. That disagreement is left standing here rather than resolved, because resolving it would mean choosing between two extension services on a medical point, and this page is not in a position to do that.

On timing, University of Arizona Cooperative Extension states that “symptoms generally develop within 20 minutes, and continue to worsen during the first 4 hours after envenomation” and that “Resolution of symptoms is usually complete within 72 hours.” It gives one instruction about the tail of that: “In rare instances, symptoms persist for more than a week, and it is recommended that patients experiencing symptoms beyond a week seek medical care.”

The same publication records that clinicians grade a patient’s symptoms on a four-point scale. That scale is a tool used by medical staff, and it is named here only so that a reader who hears it used knows what it is. It is not reproduced on this page and it is not something to apply to yourself or to a child.

On antivenom. The U.S. Food and Drug Administration lists Anascorp, proper name Centruroides (Scorpion) Immune F(ab’)2 (Equine) Injection, under STN 125335, manufactured by Rare Disease Therapeutics, Inc., with the indication “For the treatment of clinical signs of scorpion envenomation.” University of Arizona Cooperative Extension adds that it is the only available antivenom for that purpose and that “resolution of symptoms can usually be achieved within 4 hours of treatment.”

On how rare death is. Writing in 2018, University of Arizona Cooperative Extension stated that “Death is extremely rare” and that “In the United States, only four deaths in the past 11 years have occurred.” That figure is anchored to the 2018 publication date and counts the eleven years before it; it is not a statement about the period since.

Most stings are avoidable, and the sources say why. University of Arizona Cooperative Extension states: “All scorpions will sting to defend themselves, and the majority of sting incidents occur when a scorpion is accidentally grabbed, crushed against the body, or trodden on.” The practical consequences it lists are shoes and slippers at night, not storing shoes on the floor, not leaving towels or clothing on the ground indoors or out, and putting firewood straight onto the fire rather than stacking it indoors.

A 2025 study in Toxins observed defensive behaviour in wild Centruroides sculpturatus and reported that its results “failed to show consistent support for any of our four hypotheses” about sex, body size, substrate orientation and threat type. It documented the frequency of dry stings, at 11.8%, delivered to membrane-covered glass beakers under that study’s protocol. That figure describes stings to laboratory apparatus in that experiment and nothing here extends it to stings to people.

Where They Live, and How They Get In

University of Arizona Cooperative Extension states that “the Arizona bark scorpion is common around buildings of all kinds in low desert areas, and is often associated with homes and hollow-block perimeter walls”, and reports a strikingly lopsided preference: “In research studies investigating the harborage preferences of Arizona bark scorpions, 95% of the scorpions preferred hollow block walls as refuge places compared with the many other options around buildings and landscapes.” It also recommends acting on that, saying to “Stucco and cap hollow-block walls to make them less inviting harborage zones.”

On entry routes, University of Arizona Cooperative Extension describes them entering under and around poorly fitted doorways, through window vents, under exterior walls with openings, and through weep-holes in the weep screed, and then moving through the wall cavity to reach interior spaces around electrical faceplates and pipe collars. Texas A&M AgriLife Extension puts a rank order on that: “Most scorpions gain access into schools through gaps under exterior doors.” That single sentence is why the next section leads where it does.

Citing a 2017 study by Kang and Brooks, University of Arizona Cooperative Extension states that “98% of exposures occur in or around homes”, and reports from the same study that the highest sting incidence per 100,000 people occurs in Phoenix, at up to 677, and Tucson, at 584, with El Paso at 213, Oklahoma City at 209, Tulsa at 178 and Las Vegas at 170.

Two sources disagree about ceilings, and it matters. University of Arizona Cooperative Extension states that the animal “can scale walls” and “traverse across ceilings”, and describes scorpions falling from ceilings into beds, sinks, bathtubs and toilet bowls. Texas A&M AgriLife Extension states the opposite of the second half: “They will climb vertical walls, but do not generally make it far across a horizontal ceiling.” The University of Arizona pest-proofing publication agrees with Texas A&M, stating that “bark scorpions can climb vertical walls, but make little progress across ceilings.” Two of the three say ceilings are a weak point; one says they cross them. Both positions are recorded here with the source that holds them.

Two sources also disagree about the temperature at which they are active. University of Arizona Cooperative Extension states that Arizona bark scorpions are active for most of the year in low-desert areas and that “nighttime temperatures above 70° F are ideal”. A University of Arizona Backyard Gardener publication states that “Scorpions are only active when nighttime low temperatures exceed about 77 degrees F.” Both are University of Arizona Cooperative Extension publications, they are seven degrees apart, and one says “ideal” while the other says “only active”. Neither figure is used here as a threshold for anything.

On where the species occurs, the sources give three different answers. University of Arizona Cooperative Extension states that it “also colonizes small parts of California, Nevada, New Mexico, Utah, Colorado, Texas, and northwestern Mexico”. UC IPM states that the bark scorpion “is found throughout Arizona, in the extreme southeastern portion of California near Arizona, and in southwestern New Mexico”. Texas A&M AgriLife Extension states that it “is found in Arizona, New Mexico, and the Mexican states of Sonora and Chihuahua. It is also found in restricted areas of Nevada, Utah, and possibly California.” Those three statements are not the same and no merged range is offered here.

Sealing the Building

Start at the bottom of the doors, and there is a test for it. Texas A&M AgriLife Extension, having said that most scorpions get in under exterior doors, gives both the fix and the check: “This can be prevented by well-sealing door sweeps and weather-stripping. One test of doorways is to check whether light can be seen under the doorway from the inside.” The University of Arizona pest-proofing publication states the same test as a standard: “Install door sweeps and repair thresholds at the base of all exterior entry doors. No outside light should be visible underneath exterior doors when viewed from the inside at floor level.” University of Arizona Cooperative Extension puts it in one line in its scorpion publication: “Ensure door sweeps are tight fitting with no gaps.” and “Install weather-stripping around doors and windows and ensure a snug fit.”

That test is worth doing before buying anything, because it tells you whether you have a problem at all, and it tells you when you have finished.

Two measurements, and they are not in conflict. UC IPM states of the bark scorpion: “It needs only a crack of 1/16 inch to enter a home.” Texas A&M AgriLife Extension gives an instruction with a different number: “Seal gaps under flashing along roof lines and ledges that are an 1/8 inch or larger, scorpions will chase their prey even at roof lines.” The first is a fact about the animal: the smallest opening it can pass through. The second is an action threshold for one named location, telling you where to start rather than where the animal stops. A building sealed only to one eighth of an inch has not been sealed to the figure UC IPM gives.

On what to seal and with what, University of Arizona Cooperative Extension says to “Caulk around roof eaves, pipes and any other points and wall penetrations into the building.” Texas A&M AgriLife Extension names the material class: “Use weather-stripping, excluder mesh, or good quality elastomeric sealants to seal windows, building cracks, or utility penetrations.” The University of Arizona pest-proofing publication is more specific about which material lasts: “For small cracks, use good-quality silicone sealant (Fig. 6). Silicone lasts longer than latex caulking materials, as it expands and contracts more effectively with changing temperatures.”

Three silicone products are named below. They are named because they are silicone, which is the material class both Texas A&M AgriLife Extension and the University of Arizona pest-proofing publication describe, and for no other reason. Neither source names any product, and neither does this page rank these three against one another.

Two further measures from the sources need no product at all. University of Arizona Cooperative Extension says to “Keep grass closely mowed near the home. Prune bushes and overhanging tree branches away from the structure. Tree branches can provide a path to the roof for scorpions. Minimize low growing ground cover vegetation.” And the University of Arizona pest-proofing publication gives one measure aimed squarely at the group the sting material is about: “Protect an infant’s crib by placing the legs of the crib in clean wide-mouthed glass jars (scorpions cannot climb the clean glass). Pull cribs away from walls; bark scorpions can climb vertical walls, but make little progress across ceilings.”

Finding Them in the Dark

Scorpions fluoresce. Texas A&M AgriLife Extension states: “Scorpions are among the few animals that fluoresce, or glow, under UVB black light.” The University of Arizona pest-proofing publication gives the range at which that is useful: “Scorpions glow brightly under black light and are extremely conspicuous up to several yards away.” UC IPM states: “A portable black light (UV light) may be used to survey for scorpions in and around the home.”

Two University of Arizona publications give different scopes for the indoor inspection, and both are recorded here. The 2018 scorpion publication states: “Scorpions glow brightly under Ultraviolet light (UV or black light), use a UV light to inspect inside your home for scorpions before bedtime”. The 2025 Arizona Pest Management Center newsletter narrows it, saying to “use a UV light to inspect inside your bedrooms and bathrooms for scorpions before bedtime”. On timing, the 2018 publication says: “Conduct UV light collections several times during summer months between 8-11pm.”

This is also the one place any source ranks a method against chemical control. The University of Arizona pest-proofing publication states: “Repeated collections and releases far away from the house are more effective than repeated pesticide applications.”

What the sources do not say about which light to buy. Four extension services tell a reader to get one. Not one of them names a wavelength, a number of LEDs, an output figure or a battery type as a requirement. The only fitness attributes any source states are portable, battery-operated and ultraviolet: the University of Arizona pest-proofing publication asks for “a portable (battery-operated) camp light equipped with a black (UV) fluorescent bulb”, and UC IPM asks for a portable black light. Texas A&M AgriLife Extension gets closest to a comparison, noting that powerful black lights can be ordered online and weaker ones bought from pet stores and electronic retailers, but it sets no threshold between the two.

The three lights below are therefore not ranked, and no order is implied. They are listed because each is a portable ultraviolet light and each names scorpions in its own listing. No source names any of them, and this page has no basis on which to say one is better suited than another.

Do not pick one up with your hands. UC IPM states: “Scorpions can also be picked up safely with forceps that are 10 to 12 inches long, or with other long mechanical devices made for picking up small objects, and placed in a glass jar secured with a screw-type lid.” Texas A&M AgriLife Extension says the same in different words: “Long tongs or forceps, such as feeding tongs from reptile stores, are safe tools if you want to capture the scorpions to move them.” University of Arizona Cooperative Extension adds footwear to it: “Make sure that you wear boots and have long tongs if you want to capture the scorpions to move them.”

UC IPM also describes a method that needs no tool at all: place a quart-sized glass jar over the scorpion, slide a sheet of heavy construction paper under the jar, then invert it so the animal falls to the bottom, and screw a lid on. The 10 to 12 inch figure is the only product measurement any source in this pack attaches to scorpion handling, and it is the measurement each of the two products below is set against.

What to do with what you catch. University of Arizona Cooperative Extension asks readers to consider relocation over killing: “As they are beneficial to our environment please consider collecting and releasing the scorpions into the natural desert rather than killing them.” Texas A&M AgriLife Extension gives the same advice and one alternative: “Alternatively, they can be frozen.” It also notes that a bucket works as a holding container because the animal cannot climb the slippery sides.

What This Page Does Not Carry

Glue boards, and the reason is a number. UC IPM states: “Glue boards measuring 8 x 5 1/4 inches may also be useful in trapping scorpions.” Texas A&M AgriLife Extension describes what they are for: “Sticky monitoring traps readily catch scorpions and can be used to identify entry points.” That is a monitoring use, not a control method, and neither source claims a glue board reduces a population. The class is sourced and no product is named here, because the scorpion-branded glue boards that were checked do not publish a board dimension that can be measured against the figure UC IPM gives. A criterion that cannot be applied is not a criterion a page can rank on, so nothing is named rather than something being named on a guess.

Door sweeps, despite the light test being the most strongly sourced fix here. The light test above is a test of an installed door, not of a product. No source states a sweep width, a bristle length, a material or a gap tolerance, so there is no figure against which one sweep could be set beside another. The test is the useful part and it is free.

Mesh and screening. The University of Arizona pest-proofing publication gives a mesh figure, 20 mesh, in its general chapter, in a sentence that names no pest. The scorpion-specific guidance from the same authors declines to give a number and says instead to screen weep holes with coarse steel mesh, and Texas A&M AgriLife Extension says to fit weep holes with air-permeable screening or other pest exclusion materials. Two publications by the same team, and the scorpion one does not give a mesh count. That reads as deliberate, so no mesh number is applied to this animal here and no screening product is named.

Insecticides, and every source in this pack points the same way. University of Arizona Cooperative Extension states: “However, scorpions are difficult to manage with pesticides alone. Pest-proofing your home or structure is by far the most effective way to reduce scorpion contact and potential scorpion stings.” A University of Arizona Backyard Gardener publication states: “Scorpions cannot be managed using pesticides alone.” UC IPM states: “The first strategy for control is to modify the area surrounding a house, because scorpions are difficult to control with insecticides.” and explains why: “Pesticides aren’t always effective against scorpions, because they hide in cracks and crevices during daylight hours. Adult scorpions are more difficult to kill with pesticides because of their larger body size and thicker cuticle.” Texas A&M AgriLife Extension, which is the only source here that names active ingredients, still states: “Pesticides may provide some suppression of scorpions; however, they should not be relied on as a sole control method.” and “Generally, applications of insecticides for scorpions should be restricted to outdoor areas.” Its guidance is written for school pest management programmes run by licensed applicators. No chemical product is named on this page.

And nothing here promises removal. University of Arizona Cooperative Extension forecloses it: it states that eliminating scorpions from our landscapes would require chemical use it describes as extremely unhealthy and illegal, and would amount only to a temporary eradication of the pest. Where the problem is persistent, the same publication says what to do: “Scorpions are extremely difficult to eradicate. If you regularly find scorpions inside your home, call a pest management professional experienced in the management of scorpions.” Texas A&M AgriLife Extension adds one reason food control will not substitute for it: “Scorpions need very little to eat and are not easily starved out of an area.”

Questions

Sources

Every factual claim above names the source it rests on, in the sentence that makes it or in the text immediately adjacent to it, and every source named is listed below. The wording, ordering and emphasis are our own judgement and are not a finding of any source. Where two sources disagree, both are given with the source that holds each position rather than one being chosen. The products named on this page were read from their own listings on 25 August 2026 and are recorded rather than assessed; the listings read were B0BVGTM2XY, B0000CBJ7W, B0B8QPH3RW, B0D1G867Y4, B076LSWZTF, B07BK18YZD, B09QLK77RT and B07CVT3LYF, each reachable from its own card above where the disclosure sits directly beside the link. No claim is made anywhere on this page about whether any of them can be bought today.

1. University of Arizona Cooperative Extension (Dawn H. Gouge, Shujuan (Lucy) Li, Christopher Bibbs and Shaku Nair). Scorpions of the Desert Southwest United States (az1768) — the source of the identification, sting, entry and exclusion material. May 2018, originally published 2011. https://acis.cals.arizona.edu/docs/default-source/community-ipm-documents/publications/2018/az1768-2018.pdf
2. University of Arizona Cooperative Extension (Dawn H. Gouge, Shaku Nair, Shujuan Li and Tim Stock). Pest-proofing Your Home (az1677) — the source of the door light test and the silicone sealant criterion. August 2015. https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1677-2015.pdf
3. University of Arizona, Arizona Pest Management Center. Scorpions (Public Health IPM). Accessed 25 August 2026. https://acis.cals.arizona.edu/community-ipm/public-health-ipm/scorpions
4. University of Arizona, Arizona Pest Management Center. Scorpion Season is Here! — the source of the bedrooms and bathrooms inspection scope. 16 May 2025. https://acis.cals.arizona.edu/community-ipm/home-and-school-ipm-newsletters/ipm-newsletters/2025/05/16/scorpion-season-is-here!
5. University of Arizona, Arizona Pest Management Center (Dawn H. Gouge, Shujuan (Lucy) Li, Christopher Bibbs and Shaku Nair). Living with and Managing Scorpions — the source of the climbing identification character. 18 August 2022. https://acis.cals.arizona.edu/community-ipm/home-and-school-ipm-newsletters/ipm-newsletters/2022/08/18/living-with-and-managing-scorpions
6. University of Arizona Cooperative Extension, Yavapai County (adapted from Jeff Schalau). Scorpions, Backyard Gardener #184 — the source of the ultraviolet eye-safety warning and the 77 degree activity figure. 13 June 2024. https://extension.arizona.edu/sites/extension.arizona.edu/files/attachment/Scorpions.pdf
7. Texas A&M AgriLife Extension Service, School IPM. IPM Action Plan for Bark Scorpions — the source of the doorway light test, the 1/8 inch flashing threshold and the sticky monitoring trap material. Accessed 25 August 2026. https://schoolipm.tamu.edu/forms/pest-management-plans/ipm-action-plan-for-bark-scorpions/
8. UC Statewide IPM Program (E.T. Natwick, emeritus, UC Cooperative Extension Imperial County). Pest Notes: Scorpions, UC ANR Publication 74110 — the source of the 1/16 inch figure, the glue board size and the 10 to 12 inch forceps figure. Updated December 2011. https://ipm.ucanr.edu/PMG/PESTNOTES/pn74110.html
9. U.S. Food and Drug Administration. Anascorp — approved blood products register entry, STN 125335. Content current as of 2 March 2018. https://www.fda.gov/vaccines-blood-biologics/approved-blood-products/anascorp
10. Toxins (Lindsay A. Marston, Gerad A. Fox, Kim Y. Hung, Shannon J. Delo and William K. Hayes). A Sting Operation: Risk Assessment and Venom Expenditure by Arizona Bark Scorpions (Centruroides sculpturatus) in a Defensive Context. 13 April 2025, doi 10.3390/toxins17040198. https://pmc.ncbi.nlm.nih.gov/articles/PMC12030811/