TEXAS RAT SNAKE or BLACK RAT SNAKE: (Pantherophis obsoleteus)

Often called the "black snake," this is one of Missouri’s largest and most familiar snakes.  Although these snakes are shy and will avoid confrontation when possible, their habit of occupying farm buildings, sheds and old houses where mice and other rodents are plentiful often times creates conflict with humans.  The black rat snake, as the name implies, is generally shiny black, but some individuals show dark brown blotches. Small patches of red sometimes appear between the scales along the sides. The upper lip, chin, and lower part of the neck are usually white. The belly is white, mottled with gray, or may be checkered with black. Hatchlings of the black rat snake have a pale grey background with black blotches along the back.  Hatchlings are often mistaken for copperheads because their skin patterns are similar. After a year or two of growth, the color changes to a more uniform black.  The common rat snake is medium-sized, averaging 42 to 72 inches (106.7 to 183 cm) in length. At the widest point of the snake's body, its average diameter is 1.5 inches (3.8 cm). The rat snake is covered with keeled scales, and has a powerful slender body with a wedge-shaped head. The anal plate of the common rat snake is divided. A variety of subspecies is found across the United States.

 

Range 

Texas Rat Snakes or Black Rat Snakes are common and may be found across the entire state of Missouri. It may intergrade (hybridize) with the gray rat snake (Pantherophis spiloides) in the southeastern corner.  Various species of rat snakes are found from New England south through Florida and west through the eastern half of Texas and Nebraska and north again to southern Wisconsin. The black rat snake is the most widely distributed common rat snake with a range from New England south through Georgia and west across the northern parts of Alabama, Mississippi, and Louisiana, and north through Oklahoma to southern Wisconsin. There is also an isolated population in southern Canada and northern New York.  The yellow rat snake is found along the coast of the Carolinas south through Georgia and Florida. The Everglades rat snake has an isolated population in southern Florida's Everglades. The gray rat snake ranges from southern Georgia and northern Florida west through Mississippi and north to southern Kentucky. The Texas rat snake can be found in southern Oklahoma, Texas, and Louisiana.

 

Habitat

Black Rat Snakes are a forest-dwelling species, preferring rocky, wooded hillsides or sections of woods along streams and rivers (especially in former prairie and savanna areas of Missouri). They take shelter in brush piles, hollow trees, farm buildings, and old houses where mice are plenty. They are excellent climbers and often bask in trees. They overwinter in mammal burrows, rock outcrops, old rock quarries, and other places, including rotted stumps or root systems of dead trees.

 

Food Habits

Texas or Black Rat Snakes eat a variety of rodents, small rabbits, bats, bird eggs, small birds, and, on occasion, lizards. Prey is killed by constriction. They are excellent climbers and often climb trees to raid bird nests (including bluebird boxes) for eggs and young. Young rat snakes eat frogs, lizards, and insects.  These snakes feeding habits are for the most part beneficial to humans, anyone who has dealt with a mouse or rat problem can truly appreciate this natural, nonpoisonous hunter of rodents. These snakes reduce damage to crops and stored grain by rodents without the use of deadly poisons.  However, at times these snakes can also be responsible for stealing hen’s eggs or the occasional chick.

 

General Biology, Reproduction, and Behavior

Common rat snakes tend to be shy and, if possible, will avoid being confronted. If these snakes are seen and confronted by danger, they tend to freeze and remain motionless. Some adults attempt to protect themselves. They coil their body and vibrate their tails in dead leaves to simulate a rattle. If the snakes continue to be provoked, they will strike.

Rat snakes produce a foul-smelling musk and release it on the predator if they are picked up, spreading the musk around with their tail. The musk acts as a deterrent. A few of the rat snake subspecies tend to be more aggressive. The Texas rat snake and the black rat snake are very snappy, while the yellow rat snake is more passive. When alarmed, the Everglades rat snake swims away through the swampy waters. Rat snakes are excellent swimmers.  The Texas Rat Snake was long known as the black rat snake, and many know it simply as "black snake." Recent research has led scientists to reclassify this species in relation to its relatives, so its name has changed accordingly. Herpetologists, like ornithologists, carefully apply common names that correspond exactly to the scientific names. When scientific names change, the common names usually change, too.  This species is active in early April through early November. In spring, early summer, and autumn, they hunt in the daytime; in hot weather, they are nocturnal. Like most snakes, rat snakes are egg layers. Between March and May, snakes begin to emerge from their winter hibernation. After a few weeks, they begin to seek out a mate, typically in late April, May, and early June. Males tend to wait for the females to pass through their territory, and, by using pheromones, communicate and initiate the mating process with the female. The male snake approaches the female, lines up with her, and attempts to wrap his tail around hers with their vents nearly touching. Some males grasp the female with the mouth, to hold her in place and prevent her from moving away. The male then erects his hemipenes and inserts it into the female's cloaca while several small spines anchor the hemipenes firmly. Mating may last only a few minutes or span a few hours.

Five weeks later, the female lays 12 to 20 eggs. The eggs are laid in a hidden area, under hollow logs or leaves, or in abandoned burrows. The eggs hatch 65 to 70 days later. The hatchlings of common rat snakes are vigorous eaters and double their size rather quickly. If conditions are good, females sometimes produce two clutches of eggs a year.  As a predator, this snake helps keep populations of other animals, especially rodents, in check. Although it can defend itself by trying to bite, by vibrating its tail ominously, and by smearing a stinky musk on attackers, this snake often becomes food for hawks and other predators.

 

Damage and Damage Identification

 

Damage Prevention and Control Methods

 

• Exclusion - 

• Habitat Modification - 

• Trapping and Removal - 

• Shooting - 

• Other Methods - 

 

Economics of Damage and Control

There are few studies available on the damage caused by snakes. The damage they do is localized and is usually more of a nuisance than an economic loss.