# Western Diamondback Rattlesnake (*Crotalus atrox*) > The western diamondback rattlesnake (Crotalus atrox) is a large venomous pit viper of the deserts and scrublands of the southwestern United States and northern Mexico. It grows to around 1.2 m (4 ft), sometimes up to 1.5 m, and warns intruders by shaking the hollow, interlocking segments of its tail into a distinctive rattle. A carnivore that ambushes rodents, it can live 15 to 20 years in the wild and is listed as Least Concern. - **Category:** Reptile - **Conservation status (IUCN):** Least Concern - **Range:** Deserts and scrublands of the southwestern United States, including Texas and Arizona, and into northern Mexico. - **Canonical page:** https://globalanimalguide.org/animals/rattlesnake/ - **Last reviewed:** 2026-07-16 ## Scientific classification - **Kingdom:** Animalia - **Phylum:** Chordata - **Class:** Reptilia - **Order:** Squamata - **Family:** Viperidae - **Genus:** Crotalus ## Facts at a glance | Attribute | Value | | --- | --- | | Scientific name | Crotalus atrox | | Diet | Carnivore | | Habitat | Deserts, scrubland, and rocky slopes | | Lifespan | 15–20 years in the wild | | Length | 1–1.5 m (3–5 ft) | | Top speed | Up to 8 km/h (5 mph) | | Conservation status | Least Concern (IUCN) | ## The warning rattle The rattlesnake's most famous feature is the rattle at the tip of its tail, made of loose, interlocking segments of keratin. When threatened, the snake vibrates its tail so fast that the segments buzz together, producing the unmistakable warning sound. A new segment is added each time the snake sheds its skin, so the rattle grows over the animal's life, though older segments often break off. This warning lets the snake avoid conflict, since it would rather deter a large animal than waste venom defending itself. ## Venom and hunting As a pit viper, the western diamondback has a pair of heat-sensing pits between its eyes and nostrils that detect the body warmth of prey, even in darkness. It ambushes rodents, rabbits, ground birds and lizards, striking with long, hinged fangs that inject a powerful venom. The venom breaks down tissue and blood, quickly subduing prey and beginning digestion before the meal is even swallowed. After a strike the snake often releases the prey, then follows its scent trail to the fallen animal. ## Habitat and range The western diamondback is at home in the arid country of the southwestern United States and northern Mexico. It occupies deserts, dry scrubland, grassland and rocky slopes, sheltering in burrows, crevices and under rocks. It slithers across the ground on its belly, using the terrain's cover to hunt and hide from predators. During the hottest months it is most active at night, retreating to shade or shelter during the searing daytime heat. ## Size and appearance A typical adult measures around 1.2 m (4 ft) long, with large individuals reaching about 1.5 m (5 ft) and weighing close to 1.8 kg (4 lb). The snake is named for the pattern of pale-edged, diamond-shaped blotches running down its grey-brown back, which camouflages it against desert soil. Its tail bears bold black-and-white bands just before the rattle, earning it the nickname "coontail". A broad, triangular head houses the venom glands and folded fangs. ## Reproduction and life cycle Western diamondbacks give birth to live young rather than laying eggs, with a female producing a litter of roughly a dozen offspring in late summer. The newborns are fully equipped with venom and a small button of a rattle from birth, and they disperse to fend for themselves within days. In cooler parts of the range the snakes gather in communal dens to spend the winter in a dormant state called brumation. In the wild these snakes can live 15 to 20 years. ## Conservation and people The western diamondback is listed as Least Concern and remains common across much of its range. It is nonetheless persecuted through road deaths, habitat loss and organised "rattlesnake roundups", though populations have so far proved resilient. It is the leading cause of snakebite injuries in its region, but bites are rarely fatal when treated promptly with antivenom. Left alone, the snake plays a valuable role by keeping rodent numbers in check. ## Frequently asked questions ### How does a rattlesnake's rattle work? The rattle is made of loose, interlocking segments of keratin at the tip of the tail. When the snake vibrates its tail rapidly, the segments buzz against one another to produce the warning sound, and a new segment is added each time the snake sheds its skin. ### How dangerous is a western diamondback bite? The western diamondback is the leading cause of snakebite injuries in the southwestern United States, and its venom breaks down tissue and blood. Bites are painful and serious but are rarely fatal when treated promptly with antivenom. ### How big do western diamondback rattlesnakes get? Most adults are around 1.2 m (4 ft) long, with large individuals reaching about 1.5 m (5 ft) and weighing close to 1.8 kg (4 lb). It is one of the largest rattlesnake species. ### What do rattlesnakes eat? Rattlesnakes are carnivores that hunt rodents, rabbits, ground birds and lizards. The western diamondback uses heat-sensing pits to locate warm-blooded prey, then ambushes it with a venomous strike. ### Where do western diamondback rattlesnakes live? They live in the deserts, scrublands, grasslands and rocky slopes of the southwestern United States and northern Mexico. They shelter in burrows and crevices and are often active at night during the hottest months. ### How long do rattlesnakes live? Western diamondback rattlesnakes can live 15 to 20 years in the wild. Females give birth to live young in late summer, and the newborns have working venom and a small rattle button from birth. ## Sources - [IUCN Red List — Crotalus atrox.](https://www.iucnredlist.org/search?query=Crotalus%20atrox&searchType=species) - [Animal Diversity Web — Crotalus atrox. University of Michigan Museum of Zoology.](https://animaldiversity.org/accounts/Crotalus_atrox/) - [Wikipedia — Western Diamondback Rattlesnake.](https://en.wikipedia.org/wiki/Western_diamondback_rattlesnake) --- Source: Global Animal Guide (https://globalanimalguide.org/animals/rattlesnake/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.