All About the Black Ratsnake

The black ratsnake is a country classic that probably shouldn’t get the same treatment as a rattlesnake or copperhead might require.

Black Ratsnake

This black ratsnake was caught sunning on a log in Wyalusing State Park in Wisconsin.

Photo by Allen Blake Sheldon

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If you’ve ever lived on a farm in the eastern or central United States, then you’ve probably spied a shiny black ratsnake slithering through the grass. If so, what was your reaction? Curiosity? Fear? Revulsion?

Actually, appreciation might be the most appropriate response. The nonvenomous western ratsnake (Pantherophis obsoletus), or Texas black ratsnake as it is sometimes called, is an asset to farmers. Often confused in the East with the black racer snake (Coluber constrictor), black ratsnakes are capable hunters and highly efficient at catching rodents. The black ratsnake helps to control the population of mice and rats – which eats grain, fouls your toolbox and spreads disease.

Pleased to Meet You

How do you know if you’ve spotted a black ratsnake? As its name implies, this snake is black, sometimes with gray blotches. Young snakes of the species can be confused with small copperheads or other species, since in their youth – typically the first two years of life – their appearance can feature dark brown or black blotches (blotches are typically longer than they are wide) on a light gray ground color. A splash of white accents the reptile’s chin and may be visible on its underbelly.

One of the largest snakes in North America, the black ratsnake can grow up to 6 feet in length. It has a wedge-shaped head and round, lidless eyes.

Survival Skills

The black ratsnake is well equipped for survival. Though it has many predators – from raccoons, coyotes and foxes to dogs, cats, pigs and other snakes – this snake has a variety of defense mechanisms. First it freezes in place. If the threat persists, the black ratsnake may coil up and rap its tail against a hard surface (or leaves), imitating the sound of a rattlesnake. If further provoked, it may also strike or wrap its body around the predator. If seized, the black ratsnake releases a foul-smelling musk. The disgusted predator may drop its prey, though not likely, leaving the snake to slither off. Black ratsnakes typically live for 15 years, although they’ve lived up to nearly 30 years in captivity.

The black ratsnake is a stealthy hunter. It hunts by sight or smell, swimming and climbing trees with ease. These skills allow the snake to consume frogs, lizards, insects, birds, bird eggs, squirrels, moles, cottontails and shrews – as well as mice and rats. This creature maximizes camouflage by staying still and laying out flat in a lazy “S” shape, thus emulating a stick – used mainly as a protection mechanism against predators.

A member of the constrictor family, the black ratsnake seizes its prey in its mouth, slowly suffocating it by squeezing with its powerful muscles. Thanks to its detachable jaw, it can swallow a meal much larger than its head. The snake consumes whole hard objects like eggs; later, the shells will be broken in the snake’s esophagus. If food is scarce, a healthy snake can go a couple of weeks without eating.

Life Cycle

Did you know that male black ratsnakes sometimes pin each other to the ground, probably in competition for mates? The mating period typically lasts from mid-April to early June. In the late spring or early summer, the female snake lays a clutch of eggs. For her nest site, she may choose a deserted burrow, a pile of leaves, a hollow log, or a hole in a tree. She may also lay her clutch on a farm, perhaps beneath a pile of manure, compost, sawdust or debris. The black ratsnake usually lays between 12 and 20 oblong, leathery eggs.

The baby snakes hatch 65 to 70 days later. These thin, delicate creatures have pale gray scales with black patches. Unfortunately, they are sometimes confused with copperheads and killed. The hatchlings’ shiny skin grows darker over time. The young snakes have large appetites and soon double in size. Like their adult counterparts, they are mostly active during the daytime, though they occasionally forage during the evening or night.

Habitat

The black ratsnake is an adaptable creature, comfortably surviving on a variety of terrains. It can be found in fields and forests, along the edge of swamps and marshes, and in partially demolished buildings. An excellent climber, the black ratsnake may often be spotted basking on a tree limb or protruding from a tree hole. This snake may reside at sea level, high in the mountains, or anywhere in between. It mainly inhabits the Eastern states, but may live as far west as Wisconsin or Oklahoma.

If black ratsnakes live near you, they will likely leave behind a token of their presence: snakeskins. Adult snakes may shed a few times a year, whereas young, growing snakes shed every few weeks.

The skin is fragile and papery, with a shimmery diamond pattern. You might find it tucked in a tree or in the rafters of an abandoned building.

Hibernation

The black ratsnake hibernates for several months during the winter. The length of dormancy varies depending upon the climate: the warmer the weather, the sooner the snake emerges. The snake may hibernate in a natural setting like a rock crevice, tree, cave, stump or hollow log. Alternatively, it may choose a man-made location such as a stone wall, the foundation of an old building, a rock quarry or a spring house. Black ratsnakes have been known to hibernate partially underwater, such as in a well or cistern.

Hibernation is an important part of the snake’s life cycle. Poor hibernation conditions will weaken the snake and may result in its death soon after its spring emergence.

Although black ratsnakes can be a nuisance around chicken coops, they are nonetheless considered an economic asset to farmers. Without these capable hunters, rodents would multiply quickly. It is worth overcoming one’s fear of snakes and learning to view this species with curiosity and appreciation. You may find that the black ratsnake makes a better neighbor than you ever imagined.


Krista Noble is a Ph.D. candidate living among the windswept fields of Fairfield, Iowa. She has encountered many black ratsnakes in her life, and doesn’t mind their presence as long as she is properly forewarned.