Western Ratsnake
Pantherophis obsoletus • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Colubrinae, Genus: Pantherophis, Species: P. obsoletus
Central United States, ranging from the Mississippi River west to the eastern Rocky Mountains, and from southern Canada down to the Gulf of Mexico.
Look up Western Ratsnake in the Snake Encyclopedia →Venomous Status
Non-venomous; lacks fangs and venom glands (aglyphous).
Danger Level
Harmless; though they may bite if cornered or handled roughly, the bite is medically insignificant.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Colubrinae, Genus: Pantherophis, Species: P. obsoletus
Conservation
IUCN status: Least Concern. Main threats include habitat fragmentation and human persecution due to being mistaken for venomous species.
Physical Description
Features a distinct black and white checkered ventral (belly) pattern. The dorsal side of juveniles and some adults has dark blotches on a gray or tan background. Head is wider than the neck, with round pupils and slightly keeled scales.
Size & Dimensions
Specimen in image is a juvenile, likely 12-18 inches. Adults typically range from 3.5 to 6 feet, with record lengths near 8 feet.
Habitat
Highly adaptable, found in hardwood forests, swamp edges, rocky hillsides, and agricultural areas. Often climbs into trees or enters human structures like barns and garages.
Behavior & Temperament
Generally docile but can be defensive. Known for 'kinking' their bodies to look like a fallen branch and vibrating their tails in leaf litter to mimic rattlesnakes. Active primarily during the day (diurnal) or evening (crepuscular) depending on temperature.
Diet & Feeding
Constrictor that feeds on rodents, birds, and eggs. Juveniles primarily consume small lizards and frogs. They are active hunters that use smell and sight.
Reproduction
Oviparous (egg-laying). Females lay clutches of 10-30 eggs in mid-summer, typically in rotting logs or leaf mulch. Young hatch 6-8 weeks later.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Often confused with the Prairie Kingsnake (Callipeltis calligaster) or Northern Water Snake (Nerodia sipedon), but the checkered belly is a key diagnostic feature for ratsnakes.
Conservation Status
IUCN status: Least Concern. Main threats include habitat fragmentation and human persecution due to being mistaken for venomous species.
Cultural Significance
Highly valued by farmers for rodent control. They play a vital role in balancing ecosystem populations of small mammals.
Notable Features
Superb climbers known for acrobatic positions. The specimen in the photo is trapped in a sticky trap; vegetable oil is recommended to safely dissolve the glue and release the snake unharmed.