Scorpions are a common part of the natural environment in Tucson, Arizona, and encountering them is an expected reality of living in the region. These arachnids often seek shelter in and around human dwellings, particularly during the warmer months. While most species found locally are not dangerous, the primary public concern revolves around the potential for a painful or medically significant sting. Understanding the habits and specific species present in the area is key to safe coexistence.
Identifying Tucson’s Most Common Scorpion Species
Three species are most frequently encountered by residents, with one being of particular medical note. The species that warrants the most caution is the Arizona Bark Scorpion (Centruroides sculpturatus), which is the only scorpion in the United States considered to have venom that can cause severe symptoms in humans. This small scorpion measures only about two to three inches long and is typically a pale yellow or light tan color. A distinguishing physical feature is its slender build, characterized by thin, elongated pincers and a thin tail.
Unlike other local species, the Bark Scorpion is an adept climber, often found on vertical surfaces like block walls, stucco, and trees. The other common species, the Striped-tail Scorpion (Vaejovis spinigerus), is often mistaken for the Bark Scorpion, but it has a stouter body with noticeably thicker pincers. The Striped-tail Scorpion is identified by a distinctive dark, triangular marking between its eyes and dark stripes running down the tail segments.
The third common species is the Giant Desert Hairy Scorpion (Hadrurus arizonensis), which is the largest scorpion in North America, reaching lengths up to six inches. Despite its intimidating size, its sting is considered mild, comparable to a bee sting, and does not pose a significant health risk to healthy adults. A behavioral cue is that Bark Scorpions often rest with their tail tightly curved over their back, while other species tend to hold their tails to the side or straight up.
Where Scorpions Live and Hide
Scorpions are nocturnal predators, hunting insects and small prey. During the day, they seek cool, dark, and secluded shelter to avoid the intense desert heat. Their activity increases significantly during the warmer months, often peaking between late June and early August as they are drawn toward moisture and cooler temperatures.
Outdoors, scorpions frequently hide under rocks, woodpiles, landscaping timbers, and yard debris. The Arizona Bark Scorpion is known to congregate in the hollow voids of block walls, in decorative rock piles, and in irrigation boxes. They are also attracted to areas with standing water or leaking pipes.
Scorpions enter homes by exploiting gaps as narrow as 1/16 of an inch, due to their flattened bodies. Common entry points include unsealed utility penetrations, damaged weather stripping beneath doors, and unscreened weep holes in masonry. Once inside, they gravitate toward dark, undisturbed areas, such as closets, garages, baseboard crevices, and wall voids, which provide the cool seclusion they seek.
Preventing Encounters and Ensuring Safety
The best strategy for avoiding stings is proactive prevention, focusing on sealing access points and eliminating outdoor harborage. Inspecting and sealing all cracks, crevices, and gaps in the home’s foundation, walls, and utility entrances is the most effective long-term exclusion method. Ensure that all windows and doors have tight-fitting seals. Replace worn-out door sweeps to eliminate gaps at the threshold.
Reducing outdoor clutter is highly recommended, including removing yard debris, storing firewood away from the house, and keeping landscaping trimmed back from exterior walls. Shaking out clothing, towels, and shoes before use is an important daily habit, as stings often occur when a scorpion is trapped against the skin. Using a UV blacklight to inspect baseboards and outdoor areas at night can also help locate and remove scorpions, as they fluoresce a bright greenish-blue color.
If a sting occurs, the first steps involve basic first aid: cleaning the affected area with soap and water and applying a cool compress to reduce pain and swelling. Immediately contact the Poison Control Center at 1-800-222-1222 for professional medical guidance based on the victim’s symptoms and age. Emergency medical services should be contacted if the victim is a young child or elderly adult, or if severe symptoms develop, such as difficulty breathing, muscle twitching, or widespread numbness.