Are Spiders in Tucson Dangerous?

The Sonoran is the most biodiverse desert on Earth. It is home to thousands of species of insects, and along with insects come spiders. In fact, spiders are among the most common pests in our area. Spiders tend to lurk out of sight to do their hunting, but when they cross our paths, they can leave us feeling startled or frightened. The good news is that the majority of spiders in Tucson are mostly harmless to humans.

Still, there are a few species that can be troublesome. At Gecko Pest Management, we can help you design a pest control system that will limit your encounters with spiders both scary and benign.

Dangerous Spiders of Arizona

While today we often associate spiders with haunted houses, Halloween, and scary things, our ancestors did not always share this fear. Ancient humans often developed elaborate myths surrounding spiders, associating them with creation and life.

You might not be ready to trade in your discomfort around these little eight-legged creatures just yet. However, learning to recognize which arachnids are potentially dangerous can help you better protect yourself and your family.


The Arizona blonde tarantula is reclusive and docile, and they generally avoid people. They are larger spiders and can reach up to 5-inches in length, but they are voracious hunters of problem insects, making them potentially beneficial to have around.

Tarantulas live in their burrows and are shy around people. If a problem with tarantulas in or around your home, they may enter through a variety of small openings, including:

  • Foundation cracks
  • Siding
  • Crawl spaces
  • Window wells
  • Gutters
  • Torn screens
  • Open doors or windows

They are most common in homes that have an existing infestation with ants or beetles, favorite food sources for tarantulas.

Tarantulas rarely bite unless they feel threatened, but their bites can be painful. The venom is mild and can leave you feeling as though you have been stung by a wasp. A bigger threat to us as humans may be their hairs. Tarantulas have urticating hairs that they “flick” towards potential threats, and these hairs have barbs that burrow into the threat’s skin. A tarantula’s hairs can be irritating, itchy, or painful, and they can trigger an allergic reaction if they reach your eyes, nose, or mouth.

Black Widow Spiders

The Sonoran is home to 22 species of black widow spiders, one of the most venomous and dangerous spiders in the United States. Female black widow spiders possess a dangerous venom, and while they rarely kill people, they can make you extremely sick.

Black widows like to hide in sheltered, secluded areas, including:

  • Basements
  • Garages
  • Dark corners
  • Closets

Outside, they may be found in woodpiles, beneath shrubbery, near the foundation of your home, or under stones.

Small spiders, black widows measure typically less than an inch in length. The females are shiny and black with a red hourglass shape on their abdomen. Seek medical attention if you think you have been bitten by a black widow spider.

Recluse Spiders

While brown recluse spiders are the best-known of the recluse spiders, these are rare in Arizona. We are more likely to encounter the desert recluse, which is similar to the brown recluse both in looks and behavior. The desert recluse is tan to yellow-brown with six eyes and a characteristic violin shape on its back. It can reach up to 1 ½-inches long with long, thin legs.

Recluses, true to their names, are generally quite reclusive, and they often hide in:

  • Closets
  • Boxes
  • Shoes
  • Underneath furniture
  • In basements and garages

Outdoors, you may find desert recluses in firewood, beneath old logs, in rock gardens, and in piles of debris.

Desert recluses are venomous, and their bites can cause painful wounds that turn necrotic quickly. They are aggressive and will attack if they are disturbed. If you have been bitten by a recluse spider, you need to seek medical attention for proper treatment.

Wolf Spiders

Wolf spiders are larger spiders, often reaching an inch in length. They vary in color from gray to dark brown and can have peach or orange markings. They live in burrows and prey on insects at night. Only rarely are wolf spiders seen during the day, but you might spot them:

  • In your basement
  • Near doors or windows
  • Outside in grassy areas

A wolf spider bite is not usually dangerous, but it can be painful. You may have itchiness and discomfort or pain at the site of the bite if you are sensitive. This can be treated with over-the-counter antihistamines unless you have an allergy.


Scorpions are not spiders, but they are related to spiders and both belong to the arachnid class. Arizona is home to numerous species of scorpions, but only one is genuinely dangerous to people: the bark scorpion.

Much like spiders, scorpions prey on other invertebrates and are more active at night. Bark scorpions rarely reach more than a few inches in length and tend to be pale-colored. Under ultraviolet light, they glow green. While bark scorpion venom is dangerous and potentially lethal, these little arthropods are most dangerous for young children, senior citizens, older people, and those with health problems.

Bark scorpions do not intentionally invade homes but tend to hide in firewood, unkempt shrubbery, mulch, and other debris. They can accidentally enter through doors, screens, and gaps around pipes and wiring.

Ensure your screens fit well and have no holes, and apply weather stripping generously. Contact us if you continue seeing bark scorpions, and we can help you serve them their eviction notice.

Managing a Spider Problem

Controlling spiders is often a matter of controlling what attracts them the most: their prey. By removing their prey, we can often eliminate them as well. To most effectively end a spider problem, however, we also need to prevent future infestations, and that means eliminating any nests that are on your property and finding and sealing off entry points, such as cracks, crevices, damaged screens, and other access points. You will also need to remove any areas that offer them shelter, such as debris, rock piles, woodpiles, boxes, old tires, and trash. Finally, you will need to find and seal off any openings that the spiders have used as entry points to prevent new infestations.

About Gecko Pest Management

At Gecko, our Tucson pest management technicians will help you create comprehensive pest management strategies that stop your pest problems at their source. Whether you are battling beetles or stopping spiders, we work with you to get the job done. Our experienced pest technicians can identify pest hot spots and potential problems, and determine the best way to stop pests in their tracks and prevent new infestations from developing. Call our offices today to find out more about our Tucson pest control services for spiders, or to get a quote for your property.