Western Rat Snake (also known as the Black Rat Snake or Texas Rat Snake)
Pantherophis obsoletus • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Colubrinae, Genus: Pantherophis, Species: P. obsoletus
Central and Southern United States, extending from the Mississippi River west to the Rocky Mountains, and from southern Iowa down to northeastern Mexico.
Look up Western Rat Snake (also known as the Black Rat Snake or Texas Rat Snake) in the Snake Encyclopedia →Venomous Status
Non-venomous (aglyphous)
Danger Level
Harmless; while they may bite defensively if cornered or handled, the bite is medically insignificant and they pose no threat to humans or pets.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Colubrinae, Genus: Pantherophis, Species: P. obsoletus
Conservation
Least Concern (IUCN); however, they are often killed by humans due to a lack of understanding or confusion with venomous species.
Physical Description
Adults are typically dark black or very dark brown with keeled scales. In some lighting, faint blotches may be visible. The throat and chin are usually white or cream-colored. They have a distinct 'loaf of bread' body shape in cross-section and round pupils.
Size & Dimensions
Specimen appears to be an adult around 4 to 5 feet (120-150 cm). Typical species range is 3 to 6 feet, with record lengths exceeding 8 feet.
Habitat
Highly adaptable; found in hardwood forests, swampy bottomlands, rocky hillsides, and agricultural areas. They are frequently found in human environments such as barns, attics, and trash receptacles due to prey availability. Elevation ranges from sea level up to approximately 1,500 meters.
Behavior & Temperament
Diurnal and crepuscular; known for being exceptional climbers. When threatened, they often 'kink' their bodies to break up their silhouette or vibrate their tails in dry leaf litter to mimic a rattlesnake. They are generally docile but can be feisty when first encountered.
Diet & Feeding
Predominantly rodents (mice, rats), birds, and eggs. They are active foragers and powerful constrictors that use their climbing ability to raid bird nests.
Reproduction
Oviparous (egg-laying). Females lay clutches of 10 to 30 eggs in mid-summer, typically in hollow logs or compost piles, which hatch in late summer or early fall.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Often confused with the Northern Black Racer (Coluber constrictor), which has smooth scales and is more slender, or the Timber Rattlesnake (Crotalus horridus), though the lack of a rattle and the round pupils are diagnostic.
Conservation Status
Least Concern (IUCN); however, they are often killed by humans due to a lack of understanding or confusion with venomous species.
Cultural Significance
Highly valued by farmers and homeowners for natural pest control, as they can consume large numbers of disease-carrying rodents. They are one of the most common snakes encountered in suburban North America.
Notable Features
Renowned for their 'kinked' defensive posture and their incredible ability to scale vertical surfaces like brick walls or tree trunks by wedging their specialized belly scales into small crevices.