FaunaHub

Rattlesnake (genera Crotalus & Sistrurus)

ReptileSnakeVenomous

Western diamondback rattlesnake (Crotalus atrox) coiled on the ground.

Western diamondback rattlesnake (Crotalus atrox).

Image: Peter Paplanus, CC BY 2.0, via Wikimedia Commons.

Overview

Rattlesnakes are venomous pit vipers of the Americas, in the genera Crotalus and Sistrurus, instantly recognised by the segmented rattle at the tip of the tail. The animal shown here is the western diamondback rattlesnake (Crotalus atrox), a reference for this group-level overview.

This is an educational profile. Rattlesnakes are venomous wild animals; they should only be observed from a safe distance and never handled or approached. This page does not provide medical or first-aid guidance.

Conservation note: status varies by species — many rattlesnakes are widespread, while some have restricted ranges or face local declines. Verify specifics at iucnredlist.org.

Habitat & Range

Rattlesnakes live across the Americas, from deserts and grasslands to rocky hillsides, scrub, and forests, with the greatest diversity in the southwestern United States and Mexico. Many species favour warm, dry, open country with cover and basking sites.

Diet

Rattlesnakes are carnivores that prey mainly on small mammals such as rodents, along with birds and lizards. As pit vipers, they have heat-sensing facial pits that help them detect warm-blooded prey, and they use venom delivered through hinged fangs to subdue it.

Behavior

The rattle is a warning device: when threatened, a rattlesnake vibrates its tail to produce a buzzing sound that signals other animals to keep away, helping the snake avoid confrontation rather than seek it. New rattle segments are added at each skin shed. Rattlesnakes are most active in warm conditions and may shelter communally in cold weather.

Human Interaction & Conservation

Rattlesnakes help control rodent populations and generally avoid people, striking defensively only when threatened or surprised. Habitat loss, road mortality, and deliberate killing are the main conservation concerns for some species. For current status, consult authoritative sources such as the IUCN Red List.

More photos of the rattlesnake

Western diamondback rattlesnake showing its banded tail and rattle.

Western diamondback rattlesnake (Crotalus atrox).

Image: Holger Krisp, CC BY 3.0, via Wikimedia Commons.

Frequently Asked Questions — Rattlesnake

Why do rattlesnakes rattle?
The rattle is a warning signal. By vibrating the tail, a rattlesnake produces a buzzing sound that warns larger animals to stay away, reducing the chance of a dangerous encounter. It is a way to avoid conflict, not to initiate it.
How does a rattle work?
The rattle is made of loosely interlocking segments of keratin at the tip of the tail. A new segment is added each time the snake sheds its skin, and the segments knock together when the tail vibrates. Counting segments does not reliably give the snake's age, since shedding frequency varies and segments can break off.
What do rattlesnakes eat?
Rattlesnakes are carnivores that feed mainly on small mammals such as mice and rats, plus some birds and lizards. As pit vipers they detect warm prey using heat-sensitive facial pits.
What should I do if I encounter a rattlesnake?
Stop, give it plenty of space, and back away slowly — most bites happen when snakes are handled or stepped on. This page is educational only and does not provide medical or first-aid advice; for any snakebite or emergency, contact local emergency and medical services.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.