Tarantulas are native to the United States and are a natural part of the country’s ecosystem. These large, hairy spiders belong to the family Theraphosidae, which includes over a thousand species globally. In the US, they are primarily concentrated in warmer, drier regions, suiting their lifestyle as ground-dwelling burrowers. While intimidating, US species are generally docile and not considered a threat to human health.
Geographic Distribution of US Tarantulas
Native tarantula species in the US inhabit the arid landscapes of the Southwest. This range extends into the Southern and Western states, offering the hot, dry conditions and well-drained soil these spiders prefer for digging their burrows. The population is concentrated across states including Texas, Arizona, California, New Mexico, Nevada, and Utah.
Their range also pushes further north and east into states like Colorado, Oklahoma, Kansas, Arkansas, and Missouri. The Texas brown tarantula in Missouri represents one of the most northerly extensions of tarantula habitation. Their burrows can often be found beneath rocks, logs, or in areas with suitable soil.
Common Species and Identification
Nearly all North American tarantulas belong to the genus Aphonopelma, which includes about 90 species described so far. The US alone hosts approximately 29 native species. Aphonopelma species are typically large, with leg spans often exceeding six inches, and are characterized by dark colors and dense, hairy bodies.
One of the most widely distributed species is Aphonopelma hentzi, the Texas brown tarantula. Another notable species is the desert blonde tarantula, Aphonopelma chalcodes, frequently found in Arizona and identifiable by the light brown or tan hair covering the female’s body. Coloration varies; some US tarantulas are a uniform dark brown or black, while others, like the Great Basin blonde tarantula (Aphonopelma iodius), display a lighter, more golden hue.
Understanding Tarantula Behavior and Safety
US tarantulas are primarily nocturnal, spending most time hidden inside silk-lined burrows and emerging only at night to hunt. They are commonly seen wandering only during late summer and fall, when mature males leave their burrows to search for a mate. They are generally slow-moving and non-aggressive, preferring to retreat from a perceived threat rather than engage.
When threatened, US tarantulas have two main defense mechanisms. The first is the use of urticating hairs, specialized, barbed bristles found on their abdomen. The spider kicks these fine hairs toward an attacker, causing intense itching, rashes, and irritation, especially if they make contact with mucous membranes or the eyes.
The second defense is a bite, but the venom of North American species is considered low in toxicity to humans. A bite is often compared to a bee sting, resulting in localized pain and swelling but rarely causing severe medical issues unless an allergic reaction occurs.
The lifespan shows a dramatic difference between the sexes. Males reach sexual maturity at a younger age and typically live for a much shorter period, often only surviving for seven to ten years. In contrast, female tarantulas are extremely long-lived, capable of surviving for 25 to 40 years. This longevity, combined with their shy, burrowing nature, means a female may spend decades in the same protected burrow.