The term “chicken snake” is a common, non-scientific name for several species of North American rat snakes, including the Eastern, Yellow, Everglades, Gray, and Western Rat Snakes. This informal naming stems from their tendency to frequent areas where chickens are kept, often in search of rodents, birds, or eggs. Understanding the characteristics of these non-venomous snakes is helpful for accurate identification, benefiting both human safety and wildlife appreciation.
Key Physical Features
“Chicken snakes” are typically medium to large, non-venomous constrictors. Many adult Eastern Rat Snakes, for instance, commonly measure between 3.5 and 7 feet (1 to 2 meters) in total length. Their body shape is often robust, not round, but rather resembling a “loaf of bread” in cross-section.
Coloration and patterns vary significantly depending on the specific species and geographic location. Eastern Rat Snakes in the northern parts of their range are often shiny black with a white chin and throat, and a black-and-white checkerboard pattern on their belly. In contrast, adult Yellow Rat Snakes can be yellow, orange, tan, or gray, frequently displaying four dark, longitudinal stripes. Juvenile rat snakes often exhibit a gray background with dark blotches, which may fade or transform into stripes as they mature. The head of a rat snake is typically wider than its neck, and their pupils are round.
Behavioral Indicators
“Chicken snakes” are known for their impressive climbing abilities. They are highly arboreal, scaling trees, rough-barked surfaces, and even buildings with ease to access elevated habitats and prey like birds and their eggs.
When threatened, these snakes may display several defensive behaviors. They might coil their bodies, vibrate their tail rapidly—which can mimic the sound of a rattlesnake if done in dry leaves—or emit a foul-smelling musk. While they can strike if provoked, they are generally considered docile unless cornered or handled. Most rat snakes are diurnal, meaning they are active during the day, though some, like the Everglades Rat Snake, may also be active at night.
Common Look-Alikes and Distinctions
“Chicken snakes” are sometimes mistaken for other snake species, including venomous ones, due to similarities in color or defensive behaviors. A common confusion arises with venomous Copperheads (Agkistrodon contortrix) and Cottonmouths (Agkistrodon piscivorus). Rat snakes have round pupils, unlike Copperheads and Cottonmouths, which typically have vertical, slit-like pupils. However, pupil shape can be unreliable as a sole identifier, as some venomous snakes have round pupils, and non-venomous snakes can have vertical pupils.
Head shape is another distinguishing feature; pit vipers like Copperheads and Cottonmouths often have a distinctly triangular or arrowhead-shaped head due to venom glands, while rat snakes have a more elongated or “turtle-shaped” head. However, many non-venomous snakes can flatten their heads when threatened, mimicking a triangular shape. Copperheads are generally shorter, around 2-3 feet long, and have hourglass-shaped markings, which are distinct from the blotches or stripes found on rat snakes. Cottonmouths are also heavy-bodied with a broad head.
Another non-venomous snake sometimes confused with rat snakes, particularly juveniles, is the Corn Snake (Pantherophis guttatus). While both are constrictors and can have similar patterns, Corn Snakes often have more reddish or orange hues and distinct black-bordered blotches, along with a belly pattern resembling a checkerboard. Juvenile rat snakes, especially Eastern Rat Snakes, start with gray or brown blotches on a pale background, which can lead to misidentification with Copperheads.
Habitat and Role in Ecosystem
“Chicken snakes” are highly adaptable and inhabit a wide range of environments across North America. They are commonly found in woodlands, forests, farmlands, and even suburban areas, often near human dwellings. They thrive in mixed habitats that offer both cover and access to prey.
These snakes play an important role in their ecosystems as predators. Their diet primarily consists of rodents such as mice and rats, but they also consume birds, bird eggs, lizards, and frogs. By preying on rodents, rat snakes contribute to natural pest control, which benefits agricultural areas by helping to protect crops and stored grains. Their presence helps maintain a balanced ecosystem, reducing the need for chemical pesticides.