Scorpions in Surprise, Arizona

University of Arizona Extension calls the Arizona bark scorpion, Centruroides sculpturatus, the most commonly encountered house scorpion (University of Arizona Cooperative Extension, AZ1768).

The extension publication Scorpions of the Desert Southwest United States, dated May 2018, counts close to 2,000 described scorpion species worldwide, at least 100 in the U.S. and more than 50 in the desert southwestern states (University of Arizona Cooperative Extension, AZ1768). Its list of the most commonly occurring species in the low desert southwest is the bark scorpion, the Arizona giant hairy scorpion, the Arizona stripe-tailed scorpion and the yellow ground scorpion.

A separate extension sheet, Backyard Gardener number 184, dated June 13, 2024, gives a different statewide count: at least 30 species in Arizona out of about 1,400 known worldwide (University of Arizona Extension, Backyard Gardener 184). The two University of Arizona documents differ on these totals, and both are shown here as published. For any sting, AZ1768 lists the Poison Help Hotline and the Backyard Gardener sheet the Arizona Poison Control and Drug Information Center, both at 1 (800) 222-1222; this page does not cover sting care.

Last verified: October 19, 2026, by checking the two University of Arizona Extension scorpion publications, the Arizona Department of Agriculture's Office of Pest Management pages and license search, and the Youngtown station normals against this Surprise guide.

University of Arizona Extension identifies the bark scorpion by its build, describing adults as 2 to 3 inches long with relatively slender appendages and a long, slender tail (University of Arizona Cooperative Extension, AZ1768).

Color varies: the extension says bark scorpion coloration and markings are highly variable, from pale to darker with stripes or a checkered pattern (University of Arizona Cooperative Extension, AZ1768). Habits differ too: the Backyard Gardener sheet calls the bark scorpion a climbing species that never burrows, found in aboveground protected spots such as wood piles and sheds (University of Arizona Extension).

The look-alikes are ground dwellers. The stripe-tailed and yellow ground scorpions dig short burrows or scrapes in sandy soil and under surface objects, and the extension says they are often mistaken for bark scorpions even though the stripe-tailed is heavily armored and the yellow ground scorpion has a much wider, bulkier tail (University of Arizona Cooperative Extension, AZ1768). The giant hairy scorpion, the largest in the U.S. at often more than 5 inches, is called a beneficial addition to a home landscape because it eats bark scorpions.

AZ1768 also describes scorpion young in general: on average a female gives birth to about 25 to 35, which ride on her back and usually leave for good within one to three weeks after birth. Of bark scorpions it says they are not territorial and are usually found living with others, sometimes in dense populations (University of Arizona Cooperative Extension, AZ1768).

University of Arizona Extension ties scorpion activity to warm nights, though its two publications set the line differently.

The Backyard Gardener sheet says scorpions are only active when nighttime lows exceed about 77 degrees (University of Arizona Extension, Backyard Gardener 184), while AZ1768 says Arizona bark scorpions are active for most of the year in low desert areas, that nighttime temperatures above 70 degrees are ideal, and that they are less active in the coolest months, November to March (University of Arizona Cooperative Extension, AZ1768). Both are shown here as published.

At the Youngtown cooperative station, the 1991 to 2020 normal low is 79.7 degrees in July and 79.2 in August, above the Backyard Gardener's 77 degree mark, while June at 72.2 and September at 72.5 sit below it (NOAA ACIS, Youngtown normals). The extension's AZ1768 publication recommends UV light collections several times during the summer months between 8 and 11 p.m. (University of Arizona Cooperative Extension, AZ1768).

The monsoon can shift where scorpions turn up. The Backyard Gardener sheet says homes near rivers and arroyos can see an influx of scorpions during summer monsoons because scorpions may be washed downstream, and that scorpions become household pests in newly developed areas and rural settings (University of Arizona Extension). In cooler months, AZ1768 notes that bark scorpions can form over-wintering aggregations (University of Arizona Cooperative Extension, AZ1768).

Scorpions glow brightly under ultraviolet light, and AZ1768 suggests using a UV light to inspect inside a home before bedtime (University of Arizona Cooperative Extension, AZ1768); the Backyard Gardener sheet adds a warning never to look directly at an ultraviolet light (University of Arizona Extension).

AZ1768 says bark scorpions get inside buildings under and around poorly fitted doorways, through window vents and under exterior walls with openings (University of Arizona Cooperative Extension, AZ1768).

The same passage adds weep-holes in the weep screed, which lets water exit wall voids (University of Arizona Cooperative Extension, AZ1768).

Once inside a wall void, the extension says, they can move throughout the building envelope and reach interior rooms around electrical faceplates and pipe collars (University of Arizona Cooperative Extension, AZ1768). The species is common around buildings of all kinds in low desert areas and is often associated with homes and hollow-block perimeter walls, and homes with irrigated landscapes can support populations much higher than in desert wild-land areas.

Food draws them in as well. The Backyard Gardener sheet says a cricket or cockroach infestation can make scorpions more common indoors, and that scorpions can be carried into a home hidden in firewood or get in through poorly maintained door sweeps and window screens (University of Arizona Extension). AZ1768 adds that bark scorpions feed on crickets, cockroaches and many other insects and can be seen drinking from small pools of standing water (University of Arizona Cooperative Extension, AZ1768).

University of Arizona Extension says scorpions cannot be managed using pesticides alone, so the best management is to modify the habitat surrounding the home and other structures (University of Arizona Extension, Backyard Gardener 184).

The Backyard Gardener list covers sealing and caulking the home, replacing door sweeps when necessary, reducing clutter next to the structure, pruning bushes and overhanging branches away from the walls, keeping only small amounts of firewood indoors, and discouraging the insects scorpions eat (University of Arizona Extension). AZ1768 adds installing weather-stripping around doors and windows with a snug fit, keeping grass closely mowed near the home, minimizing low growing ground cover, and storing garbage containers in a frame that holds them above ground level (University of Arizona Cooperative Extension, AZ1768).

Tree branches are on the AZ1768 list because, the extension says, they can give scorpions a path to the roof (University of Arizona Cooperative Extension, AZ1768). Firewood brought in from outdoor storage should go directly on the fire rather than being stacked inside, and wood, rocks, clutter or debris should not be allowed to build up against the house (AZ1768).

For scorpions that are caught, AZ1768 asks residents to consider collecting them with boots on and long tongs and releasing them into the natural desert rather than killing them, because scorpions are beneficial to the environment (University of Arizona Cooperative Extension, AZ1768). The Backyard Gardener sheet describes the same practice of picking them up with kitchen tongs, sealing them in a jar and relocating them to undisturbed natural areas (University of Arizona Extension).

A Surprise homeowner can confirm a pest control company's license through the Arizona Department of Agriculture's online license search, which has separate links for Office of Pest Management business licenses and individual licenses (Arizona Department of Agriculture, license search).

The Office of Pest Management regulates Arizona's non-agricultural, or structural, pest management industry, licensing the businesses and applicators that provide pest, termite, weed, public health and aquatic pest management as well as structural fumigation; its inspectors conduct routine inspections of pest management businesses and it investigates consumer complaints, including complaints about unlicensed pest management activity (Arizona Department of Agriculture, Office of Pest Management).

Under the department's FAQ, and subject to exemptions in state statute, anyone who identifies infestations, makes inspections to identify them, writes inspection reports, estimates or bids, or applies pesticides as a business needs a business license, and certified applicators may apply general or restricted-use pesticides while employed by a licensed business or a political subdivision, according to label directions (Arizona Department of Agriculture, Pest Management FAQs). The FAQ also says consumers may obtain, online or in writing, the license status of any business or individual licensee, including a history of complaints filed against them.

When a complaint falls within its jurisdiction, the FAQ says it is assigned to an inspector as an inquiry, a threshold investigation to determine if violations exist, and a citation is drafted if violations are found (Arizona Department of Agriculture). The Office of Pest Management licensing desk is (602) 542-3578, an inspector can be reached at (602) 542-4373, option 3, and office hours are Monday to Friday, 8:00 AM to 5:00 PM, at 1110 W Washington Street, Suite 450, Phoenix (Office of Pest Management).