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Is this a bark scorpion? Arizona scorpion ID guide.
Arizona has more than 30 scorpion species, but only one — the bark scorpion — produces a sting that is medically significant. Here is how to tell a bark scorpion from the two other most-common Arizona scorpions in seconds, what the sting actually feels like, when to call Poison Control, and what to do if you find one inside.
The 30-second answer
Slender + light tan + climbs walls + holds tail to the side = bark scorpion.
Bark scorpions are the small, slender, climbing scorpions. They are also the medically dangerous ones. The two other most-common Arizona scorpions — stripetail and giant hairy desert — are bulkier, ground-dwelling, and produce stings comparable to a bee or wasp.
Six features that identify a bark scorpion
Body, pincers, tail, behavior — what to look for.
Body size and color
Bark scorpions are small and slender — 2 to 3 inches with the tail, light tan to translucent yellow, sometimes with darker striping on the back. Compare against a quarter for scale. Larger, darker, or hairier scorpions are not bark scorpions.
Pincer shape
Bark scorpions have slim, slender pincers (pedipalps) — thinner than the body. Most other Arizona scorpions have noticeably bulkier, more crab-like pincers.
Tail position at rest
Bark scorpions hold their tail to the side, often laid flat. Other Arizona scorpions curl the tail over the back in classic scorpion silhouette. Tail to the side at rest is a strong bark scorpion indicator.
Climbing behavior
Bark scorpions climb walls, ceilings, fences, and trees. They are the only Arizona scorpion that does this. If you see a scorpion on a vertical surface, it is almost certainly a bark scorpion.
UV black light glow
All scorpions glow blue-green under UV black light. The test confirms it is a scorpion but does not distinguish species — use it to find them, then use body features to ID the species.
Where you found it
Bark scorpions found indoors (bedroom, bathroom, kitchen, closet) are typical. Stripetail or giant hairy desert scorpions found indoors are unusual — they prefer ground-level desert habitat.
Species comparison
The three most-common Arizona scorpions, side by side.
Bark scorpion (Centruroides sculpturatus)
Medically dangerous
Look for
Slender, light tan to translucent, 2-3 inches with tail, slim pincers and a thin tail. Holds tail to the SIDE, not curled over the back.
Behavior
Only Arizona scorpion that climbs walls and ceilings. Active at night. Hides during the day in tight cracks, behind baseboards, in shoes left outside, between sheets.
Sting
Severe pain, numbness, and tingling for 24-72 hours in healthy adults. Children, elderly, and allergic individuals can have severe neurological reactions. Call Arizona Poison Control: 1-800-222-1222.
Arizona stripetail (Vaejovis spinigerus)
Not medically dangerous
Look for
About 2 inches long, dark brown to nearly black, with distinctive dark stripes running down the tail segments. Stockier than bark scorpion with broader pincers.
Behavior
Ground-dwelling, does not climb walls. Common throughout Arizona deserts and yards. Often found under rocks, wood debris, and irrigation boxes.
Sting
Painful — comparable to a wasp or bee sting — but not medically dangerous to healthy adults. Localized pain and swelling that resolves in hours to a day.
Giant hairy desert scorpion (Hadrurus arizonensis)
Not medically dangerous
Look for
The largest scorpion in North America, 4-7 inches long. Yellow-tan body with a darker back, and visible brown hairs covering the legs and tail. Bulky build, thick pincers.
Behavior
Ground-dwelling, slow, does not climb walls. Mostly found in open desert and rural areas. Less commonly seen in suburban homes than bark scorpions.
Sting
Painful sting, comparable to a bee sting. Not medically dangerous to healthy adults. The size of the scorpion can be alarming but the venom is mild.
If you are stung
Bark scorpion sting reactions by severity.
The Arizona Poison Control Center number is 1-800-222-1222 — free, available 24/7, and the right first call for any scorpion sting if you are unsure of the severity.
Mild reaction (most healthy adults)
Severe pain at the sting site, numbness, tingling, and a 'fizzing' or electric sensation. Pain peaks at 30-60 minutes and gradually fades over 24-72 hours. Treat with ice, acetaminophen or ibuprofen, and rest. No emergency response needed for an isolated mild reaction.
Moderate reaction (concerning)
Pain spreading beyond the sting site, muscle twitching, restlessness, sweating, blurred vision. Adults with these symptoms should be monitored and call Arizona Poison Control: 1-800-222-1222 for guidance.
Severe reaction (emergency)
Difficulty breathing, severe muscle twitching, drooling, eye-rolling, slurred speech, severe agitation, or loss of muscle control. Children under 6, the elderly, allergic individuals, and anyone with severe symptoms need ER care. Antivenom (Anascorp) is available at most Arizona hospitals and is highly effective.
Arizona Poison Control Center: 1-800-222-1222 — free, 24/7. They can advise on whether the reaction requires an ER visit.
What to do next
If you found a bark scorpion inside, the next step is not a spray.
One bark scorpion inside almost always means more are nearby. They come from outside through entry points the homeowner usually has not seen — weep screeds at the base of stucco, garage door gaps, soffit corners, utility penetrations. Effective scorpion control combines exterior perimeter and harborage treatment, UV-based inspection to find active areas, and sealing recommendations to close the gaps that let them in. Over-the-counter spray on a scorpion sitting on a wall does not solve the source.
Do trap the scorpion under a container so identification is certain.
Do shake out shoes left in the garage, check beds and towels before use, wear closed-toe shoes at night.
Do get a scorpion-focused inspection so the source and entry points are addressed.
Do not assume one is the only one or that general pest control covers it.
Related identification guides
More Arizona pest ID help.
Frequently asked questions
Bark scorpion identification FAQs.
How do I tell a bark scorpion from other Arizona scorpions?
Bark scorpions are slender and light tan (often translucent looking), about 2 to 3 inches long including the tail, with slim pincers and a thin tail. They are the only Arizona scorpion that climbs walls and ceilings, and they hold their tail to the side rather than curled over the back. They glow bright blue-green under a UV black light. Other Arizona scorpions (Arizona stripetail, giant hairy desert scorpion) are bulkier, slower, do not climb walls, and have thicker pincers.
Are bark scorpion stings dangerous?
Bark scorpion stings are the only medically significant scorpion sting in North America. Most healthy adults experience severe pain, numbness, and tingling at the sting site for 24 to 72 hours, and that is the full reaction. Small children, the elderly, and people with severe allergies can have a more serious reaction: difficulty breathing, muscle twitching, severe neurological symptoms, drooling, or eye-rolling. For a child under 6, an elderly person, or anyone with severe symptoms, call the Arizona Poison Control Center at 1-800-222-1222 or go to an emergency room.
Why do bark scorpions appear inside Arizona homes?
Bark scorpions are excellent climbers and very small — they can fit through a gap thinner than a credit card. They follow insects, moisture, and shelter, which often leads them through garage door gaps, weep screeds at the base of stucco, attic and soffit gaps, and around pipe penetrations. Once inside, they hide in dark, low-traffic spaces during the day: behind baseboards, in closets, under sinks, in bathrooms, between sheets in unmade guest beds, inside shoes left in the garage. Homes near desert edges, with citrus or palms, or with active insect populations are at higher risk.
What is the UV black light test and why does it work?
All scorpions, including bark scorpions, contain a substance in their exoskeleton (likely beta-carboline) that fluoresces under ultraviolet light. A handheld UV black light shined on a wall, floor, or landscape area at night will make any scorpion glow bright blue-green. The test works because scorpions are nocturnal and hidden during the day. A 15-minute UV walk of the perimeter at night will usually reveal scorpions that would otherwise stay hidden. Firehouse uses this technique on scorpion inspections in Gilbert, Mesa, Chandler, Scottsdale, and the East Valley.
What should I do if I find a bark scorpion inside?
Trap it under a clear container if you can do so safely — that confirms identification and removes the immediate threat. Wear closed-toed shoes and use a long object (broom handle, dustpan). Do not handle it. Then look for the entry point: scan baseboards, the bottom of doors, garage edges, weep screeds, and any spot where outside meets inside. One scorpion inside almost always means the path is open for more, so the next step is a scorpion-focused inspection — not an interior spray.
Will general pest control kill scorpions?
General pest control reduces the insects that scorpions eat (crickets, roaches, ants), which lowers scorpion pressure over time. But scorpions are not directly killed by most perimeter sprays — their thick exoskeleton and behavior protect them. Effective scorpion control combines exterior perimeter and harborage treatment, UV-based inspection to locate active areas, sealing recommendations to close access points, and ongoing pressure reduction. If you are seeing live scorpions, ask for scorpion control specifically rather than assuming general pest service covers it.
Take control today
Found a scorpion inside?
Firehouse can run a UV scorpion inspection at night, find entry points, treat the perimeter and harborage, and recommend sealing. One scorpion sighting is almost always a sign the path is open — the inspection finds out where.