Western Rat Snake
Pantherophis obsoletus • Order: Squamata; Suborder: Serpentes; Family: Colubridae; Subfamily: Colubrinae; Genus: Pantherophis; Species: P. obsoletus
Widespread throughout the central United States, from the Mississippi River west to the Rocky Mountains and from southern Canada south into northern Mexico.
Look up Western Rat Snake in the Snake Encyclopedia →Venomous Status
Non-venomous; aglyphous (lacks specialized fangs).
Danger Level
Harmless; they generally prefer to flee or remain still to avoid detection. Bite may cause minor scratches but poses no serious health risk to humans.
Family
Order: Squamata; Suborder: Serpentes; Family: Colubridae; Subfamily: Colubrinae; Genus: Pantherophis; Species: P. obsoletus
Conservation
IUCN Red List: Least Concern. Generally abundant, though they face threats from habitat fragmentation and intentional killing due to fear or confusion with venomous species.
Physical Description
Large, heavy-bodied snake. Adults often appear solid black or very dark brown with faint traces of a blotched pattern. The chin and throat are typically white or cream. Scales are weakly keeled and the pupils are round.
Size & Dimensions
The specimen in the image appears to be a large adult, likely 4-5 feet in length. Species typical size range is 3.5 to 6 feet, with a maximum record of 8.5 feet.
Habitat
Highly adaptable to diverse environments including hardwood forests, river floodplains, rocky hillsides, and suburban landscapes. They are adept climbers frequently found in trees or on man-made structures.
Behavior & Temperament
Predominantly diurnal but active at night during hot summer months. Known for their climbing ability and for 'kinking' their bodies when threatened. They may rattle their tails in leaf litter to mimic rattlesnakes.
Diet & Feeding
An active forager and powerful constrictor. Diet consists primarily of rodents, birds, and bird eggs. Commonly referred to as 'chicken snakes' due to their habit of entering chicken coops for eggs.
Reproduction
Oviparous (egg-laying). Females lay clutches of 10 to 20 eggs in mid-summer, typically in hollow logs, mulch piles, or leaf litter. Hatchlings emerge in late summer or autumn.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Often confused with the North American Racer (Coluber constrictor), which has smooth scales and is more slender, or the Timber Rattlesnake (Crotalus horridus), which has a triangular head and rattles.
Conservation Status
IUCN Red List: Least Concern. Generally abundant, though they face threats from habitat fragmentation and intentional killing due to fear or confusion with venomous species.
Cultural Significance
Highly valued by farmers and homeowners for their ability to control rodent populations. They are a staple of North American herpetofauna and frequently encountered in residential areas.
Notable Features
Renowned for their exceptional climbing skills, often appearing in unusual vertical positions on brick walls, trees, or rafters, as evidenced by this specimen's presence on a stone pillar.