Western Pigmy Rattlesnake

Sistrurus miliarius streckeriOrder: Squamata, Suborder: Serpentes, Family: Viperidae, Subfamily: Crotalinae, Genus: Sistrurus, Species: Sistrurus miliarius

Western Pigmy Rattlesnake

Venomous Status

Venomous (Solenoglyphous)

Danger Level

Moderate Risk. While their small size means lower venom yields, they are highly defensive and can cause severe localized reactions. Medical attention is always required for a bite.

Geographic Range

Natural range includes the south-central United States, specifically from East Texas through Oklahoma, Arkansas, Louisiana, and into Missouri and Tennessee. The specimen in San Jacinto County, Texas, is within its native range.

Conservation Status

Least Concern (IUCN), though localized populations may face threats from habitat loss and road mortality.

Physical Description

Small, stout body with grayish to brownish ground color and dark, irregular blotches along the back. It often features a thin reddish-orange dorsal stripe. The head is distinct from the neck with a dark line through the eye. Tail ends in a tiny, barely audible rattle. Eyes have vertical pupils. Scales are keeled.

Size & Dimensions

The specimen in the photo appears to be a juvenile or small adult, approximately 6-8 inches. Adults typically range from 14 to 22 inches (36-56 cm).

Habitat

Inhabits pine-hardwood forests, mixed woods, and areas near water such as marshes or floodplains. They are often found in leaf litter or under logs from sea level to moderate elevations.

Behavior & Temperament

Known for a 'feisty' temperament; they are quick to strike and vibrate their tails when threatened, though the rattle is so small it sounds like a buzzing insect. Primarily crepuscular or nocturnal during hot months.

Diet & Feeding

Feeds on a variety of small prey including lizards, small snakes, frogs, and occasionally small rodents or large insects. They use both ambush and active foraging strategies.

Reproduction

Ovoviviparous (gives birth to live young). Litters typically consist of 3 to 8 neonates, born in late summer or early fall.

Venom & Safety

Venom Type

Hemotoxic venom that causes localized tissue damage, pain, and swelling; however, due to small yield, it is rarely fatal to healthy adult humans.

First Aid Advice

Keep the victim calm and the affected limb immobilized at or slightly below heart level. Remove restrictive jewelry. Seek immediate emergency medical care at a hospital equipped with antivenom (CroFab). Do not use tourniquets or attempt to 'suck out' venom.

Look-alikes

Commonly confused with juvenile North American Racers (Coluber constrictor) or juvenile Ratsnakes (Pantherophis), but distinguished by the heat-sensing pits, vertical pupils, and presence of a rattle.

Conservation Status

Least Concern (IUCN), though localized populations may face threats from habitat loss and road mortality.

Cultural Significance

Often feared due to its rattlesnake status, it plays a vital ecological role in controlling populations of small vertebrates and is a subject of study for its unique venom proteins.

Notable Features

The 'Sistrurus' genus is distinguished from 'Crotalus' (larger rattlesnakes) by having nine large plates on the top of the head rather than many small scales. Its 'insect-like' rattle sound is a signature characteristic.

Identified on 3/6/2026