Is it a bark scorpion?
Yuma has several scorpion species. Only one of them is a medical concern, and telling them apart takes about ten seconds once you know what to look at.
Four checks
- 1. Does it climb?
- This is the one that settles it. Bark scorpions climb walls, cabinets and ceilings. Every other scorpion in the region stays on the ground. Found it above floor level — assume bark scorpion.
- 2. Pincers: slender or bulky?
- Bark scorpion pincers are thin, almost delicate. The desert hairy scorpion has thick, crab-like claws. As a rule of thumb across scorpions: thin pincers, stronger venom.
- 3. Size and colour
- Two to three inches, light tan to yellowish brown, slim body. The desert hairy is noticeably bigger — up to five inches — darker, and covered in fine hairs.
- 4. How is it resting?
- Bark scorpions hang upside down. Under shoes, under towels, on the underside of patio furniture, inside a blanket that has been shaken out and dropped.
The ultraviolet test
Scorpion cuticle fluoresces. Under a UV flashlight they shine bright blue-green and become impossible to miss, including the young ones you would never spot otherwise.
A UV flashlight costs about ten dollars and is the most useful purchase a Yuma homeowner can make. Check the base of block walls, around irrigation boxes, under the edge of pavers, and along the foundation on the shaded side of the house.
One caveat. Recently moulted scorpions do not glow. If you find none under UV but keep seeing them indoors, that is not proof of absence.
What the young ones look like
Juveniles are pale, sometimes almost translucent, and small enough to be mistaken for a spider at a glance. Their venom is no weaker than an adult's. Seeing small ones indoors is a stronger signal than seeing a large one: it suggests they are breeding in or against the structure rather than wandering in.
Not sure what you found?Send a photo or call — identification costs nothing