Arizona wildlife in forest, mountain and desert habitats

Arizona Venomous Animals

Originally written by Tony Subia

Updated by AZ Leisure Staff Writers on October 24, 2026

Western diamondback rattlesnake in rocky Arizona desert habitat in a defensive posture

Arizona is home to a diverse group of venomous animals, including rattlesnakes, bark scorpions, black widow spiders, native recluse spiders, Gila monsters and giant desert centipedes. These animals live in habitats ranging from Sonoran Desert washes and rocky foothills to wooded mountain areas, residential yards and buildings. Most avoid people and bite or sting only when threatened, trapped or accidentally disturbed. Learning how to identify Arizona's venomous wildlife, avoid close encounters and respond appropriately to a bite or sting can help residents, hikers, campers and visitors explore the state more safely.

Common Venomous Animals
Venomous Spiders
Arizona Scorpions
Venomous Snakes
Gila Monsters
Desert Centipedes
Avoiding Bites And Stings
What To Do If Bitten Or Stung
FAQ

Venomous Versus Poisonous Animals

Venomous and poisonous do not mean exactly the same thing. Venom is delivered through a bite, sting or specialized structure, while poison causes harm when it is swallowed, inhaled, touched or otherwise absorbed. Rattlesnakes, scorpions, Gila monsters and certain spiders are venomous because they deliver venom directly into another animal or person. This page focuses on Arizona animals that can deliver venom through bites or stings.

Most Common Venomous Animals In Arizona

Arizona's best-known venomous animals include rattlesnakes, bark scorpions, black widow spiders, native recluse spiders, Gila monsters and giant desert centipedes. Encounters are most common during warmer weather, although activity varies by species, elevation and habitat. Desert and foothill areas generally support the greatest variety, but rattlesnakes and some spiders also occur in Arizona's mountain regions.

Venom is used primarily to capture prey and sometimes as a defense against threats. Most animals would rather retreat than confront a person. Serious injuries are uncommon when wildlife is left alone, but any suspected envenomation should be treated seriously and evaluated with guidance from a medical professional or poison-control specialist.

Venomous Spiders In Arizona

Black widow spiders and native recluse spiders are the Arizona spiders of greatest medical concern. Both generally avoid people and usually bite only when pressed against the skin, trapped in clothing or disturbed in a sheltered location.

Black Widow Spider

Female black widow spider on an irregular web with a red hourglass marking visible on its abdomen

Adult female black widows have glossy black bodies and commonly display a red or orange hourglass-shaped marking beneath the abdomen. They often build irregular webs in protected places such as woodpiles, garages, storage areas, outdoor furniture and utility boxes.

Arizona Recluse Spider

Arizona recluse spider with a tan body and long slender legs in a natural desert setting

The true brown recluse is not considered a normal Arizona resident. Arizona does, however, have native recluse species, including the Arizona recluse and desert recluse. Identification based only on color or a violin-shaped marking can be unreliable, so suspected medically significant spider bites should be evaluated by a healthcare professional.

Arizona Tarantulas

Close-up of a hairy Arizona desert tarantula walking across rocky desert soil

Arizona tarantulas may appear intimidating, but their venom is generally mild. Their abdominal hairs can also irritate the skin, eyes and respiratory system when released defensively. Tarantulas should be observed from a distance and left undisturbed.

Arizona Scorpions

All scorpions produce venom, but the effects of a sting vary by species and individual sensitivity. Arizona scorpions use the stinger at the end of the tail to subdue prey and defend themselves. Many stings cause localized pain, tingling or numbness that improves without hospital treatment.

Arizona Bark Scorpion

Arizona bark scorpion in natural desert habitat with pincers extended and curved stinging tail

The Arizona bark scorpion is the state's scorpion of greatest medical concern. Its sting can cause severe pain, numbness, muscle twitching, abnormal eye movements, difficulty swallowing or breathing and other neurological symptoms. Young children are particularly vulnerable. Call the Arizona Poison and Drug Information Center at 1-800-222-1222 for immediate guidance after a suspected bark scorpion sting. Call 911 for breathing difficulty, loss of consciousness, seizures or other life-threatening symptoms.

Venomous Snakes In Arizona

Arizona supports about 15 species of rattlesnakes, more than any other state. Species distribution varies by elevation, vegetation and region. Western diamondback rattlesnakes are widely encountered in desert areas, while several other species occupy mountains, grasslands, canyons and specialized habitats.

Western Diamondback Rattlesnake

Western diamondback rattlesnake sheltered beneath the edge of a rock in Arizona desert habitat

The western diamondback rattlesnake is one of Arizona's most recognizable venomous snakes. It inhabits deserts, rocky foothills, grasslands and other warm, dry environments. Its diamond-shaped back markings and black-and-white bands near the tail help distinguish it from many other rattlesnakes, although identifying snakes from markings alone is not always reliable.

Western Diamondback Rattlesnake In Grassland Habitat

Western diamondback rattlesnake moving through dry grasses and desert weeds in Arizona

Western diamondbacks also move through grassy and weedy areas where vegetation provides cover and attracts small mammals. Rattlesnake venom can cause severe pain, swelling, tissue injury, abnormal bleeding and other serious symptoms. Anyone bitten by a rattlesnake should seek emergency medical care immediately rather than waiting for symptoms to develop. Do not capture or kill the snake; a photograph taken from a safe distance may help with identification, but treatment should never be delayed.

Sonoran Coral Snake

Sonoran coral snake with red black and pale yellow bands moving across rocky Arizona desert ground

The Sonoran coral snake is another venomous Arizona species. It is small, secretive and rarely involved in bites. Its red, yellow and black banding can resemble harmless species, so color rhymes should not be relied upon for identification. Never handle an unfamiliar snake.

Gila Monster

Arizona Gila Monster

Arizona Gila monster with black and orange patterned scales walking through natural Sonoran Desert habitat

The Gila monster is a large, heavy-bodied venomous lizard native to Arizona and other parts of the Southwest. Its distinctive black body is patterned with orange, pink or yellow markings. Gila monsters spend much of their lives underground and are encountered most often during warm spring and early-summer conditions.

Gila monsters are slow-moving and do not chase people, but they may bite when handled, cornered or threatened. They deliver venom while maintaining a powerful chewing grip. Anyone bitten by a Gila monster should call 911 or seek emergency medical care and contact the Arizona Poison and Drug Information Center at 1-800-222-1222. Do not attempt to pull the animal off with bare hands.

Learn more about Gila monsters in Arizona.

Centipedes

Several centipede species occur in Arizona, including the large giant desert centipede. Centipedes have flattened segmented bodies, with one pair of legs attached to most body segments. The first pair of modified legs forms venom-delivering claws near the head.

Arizona Giant Desert Centipedes

Arizona giant desert centipede with a reddish brown segmented body and yellow orange legs crawling across rocky desert soil

A centipede bite can cause immediate pain, redness and swelling. Symptoms are usually localized and short-lived, but severe or persistent pain may require urgent medical evaluation. Call 1-800-222-1222 for poison-control guidance, particularly if symptoms are unusual, rapidly worsening or involve a young child or medically vulnerable person.

What To Do When You Encounter Venomous Wildlife

If you encounter a rattlesnake, scorpion, Gila monster or other potentially venomous animal in Arizona, stop at a safe distance and allow it to move away. Do not approach for a closer photograph, attempt to pick it up or try to move it with your hands. Keep children and pets away from the animal.

Rattlesnakes may remain silent rather than rattle, and some venomous animals are difficult to distinguish from harmless species. Avoid relying on color patterns, body shape or behavior alone to determine whether an animal is safe to handle. When wildlife is discovered near a doorway, patio or heavily used area, keep the area clear and contact a qualified wildlife removal professional if necessary.

How To Avoid Venomous Animal Bites And Stings

Watch where you place your hands and feet while hiking, climbing or moving rocks.
Use a flashlight outdoors after dark.
Wear sturdy shoes rather than sandals in desert and rocky areas.
Shake out shoes, clothing, towels and sleeping bags before using them.
Keep garages, patios and storage areas free of clutter.
Do not reach into holes, woodpiles or dark spaces without looking first.
Keep tents zipped and inspect bedding while camping.
Never handle a rattlesnake, Gila monster, scorpion or unfamiliar spider.
Give wildlife a clear escape route and move away slowly.
Teach children to observe wild animals without touching them.

What To Do If Bitten Or Stung

The information on this page is provided for general awareness and should not be used to diagnose or treat a bite or sting. Call 911 for trouble breathing, loss of consciousness, seizures, severe weakness or other life-threatening symptoms.

For a suspected rattlesnake bite, remain as calm and still as possible, remove rings or tight items near the affected area and seek emergency medical care immediately. Do not wait for symptoms to appear. Do not apply ice, cut the wound, attempt to suck out venom, use electric shock or apply a tourniquet.

For scorpion stings, spider bites, centipede bites or uncertain exposures, contact the Arizona Poison and Drug Information Center for case-specific guidance. A suspected Gila monster bite should be evaluated at a medical facility.

Arizona Poison and Drug Information Center
1-800-222-1222
Available 24 hours a day

Arizona Venomous Animals FAQ

What is the most dangerous venomous animal in Arizona?

Risk depends on the circumstances, but rattlesnake bites can cause severe and potentially life-threatening injury. Arizona bark scorpion stings can also cause serious neurological symptoms, particularly in young children.

How many rattlesnake species live in Arizona?

Arizona has about 15 rattlesnake species, with distributions determined by elevation, habitat and region.

Are all Arizona scorpions dangerous?

All scorpions are venomous, but most Arizona species cause primarily localized pain. The Arizona bark scorpion is the species of greatest medical concern.

Does Arizona have brown recluse spiders?

The true brown recluse is not considered a normal Arizona resident. Arizona has several native recluse species, including the Arizona recluse and desert recluse.