Are Tarantulas Poisonous?

Genus Aphonopelma

Common Questions About Tarantulas

Are tarantulas poisonous?
What should I do if a tarantula bites me?
How can I keep tarantulas out of my home and yard?
Tarantula Appearance, Anatomy, Habitat and Prey
Health and Medical Disclaimer

Are Tarantulas Venomous?

In the face of a threat or a perceived threat, a typical American tarantula has two lines of defense. It can use its fangs to inflict a bite, or it can use its urticating (barbed and mildly venomous) abdominal hairs to cause soft tissue or eye irritation. Fortunately, while painful and aggravating, the tarantula's fangs or or hairs appear to cause no long term damage in most cases.

Tarantula on stucco wall. See one in action in this video.
Photo by Jay Sharp.

The Fangs

According to Barron's Tarantulas and Other Arachnids, the tarantula's "mouth parts include the muscular fang bases and the attached backward-pointing fangs… The tarantula's venom glands are inside the basal part."

When it attacks prey such as an insect or another spider, the tarantula swiftly drives its fangs into the body and delivers the venom, which liquefies the insides, according to the Tarantula Facts internet site. The tarantula dines on the resultant "soup."
If a tarantula should bite you – probably after warning you to back off by raising its front legs and displaying its fangs in a threat posture – it will likely inflict a pain comparable to that resulting from a bee or wasp sting. Brent Hendrixson, in his article, "So You Found A Tarantula!" on the American Tarantula Society internet site, says that the tarantula's "venom is of no medical significance, and contrary to popular belief, nobody has ever died from such a bite…"

Other authorities, however, say that a tarantula's bite can trigger an allergic reaction, making you gasp or feel ill, calling for a visit to the doctor. (See Treatments of Tarantula-inflicted Injuries.)

The Urticating Hairs

According to Robert J. Wolff, Ph. D., writing for the Carolina Biological Supply Company internet site, the tarantula's urticating hairs can "penetrate skin, mucus membranes, and eyes." If they come into "contact with soft tissues they dig into the tissue and cause an urtication or irritation."

Threatened by a skunk, for example, the tarantula may use its legs to cast its hairs into the animal's face, "causing the eyes to water, the nose to itch, the breathing passages to swell shut, and the lips and tongue to become irritated."

If a tarantula should cast its hairs into your face or inner arm – should you get too close, especially to a surly spider – it will cause redness and itching of your skin for a couple of days and irritation of your lips, tongue and eyes. A tarantula's urticating hairs can produce allergic reactions, including significant skin rashes, swelling and breathing problems, calling for medical attention. (See Treatments of Tarantula-inflicted Injuries.)

by Jay Sharp

More pictures of Tarantulas by Kenton Elliott at Calico. They were photographed on Main Street at Calico Ghost town in California.

Watch video of a Tarantula and a Tarantula Hawk.