Great Plains Ratsnake

Image of a Great Plains ratsnake
Scientific Name
Pantherophis emoryi
Colubridae (nonvenomous snakes) in the order Squamata (lizards and snakes)

The Great Plains ratsnake is a medium-sized gray snake with numerous brown blotches along the body, a brown eye stripe, and a spear-point marking on top of the head. The ground color is light gray or tan; along the back, there are 25–45 brown blotches bordered with black. A dark brown stripe between the eyes extends through each eye, along the sides of the head, and onto the neck. There is a spearhead-shaped marking on top of the head. The belly is white with bold, squarish black markings, and there are black or dark gray stripes under the tail.

Like other ratsnakes, Great Plains ratsnakes vibrate their tails when alarmed and will bite to defend themselves, but the bite is harmless.

Similar species:

  • The prairie kingsnake looks similar, and it is more common in our state. Its markings are different, including two rows of smaller blotches along the sides; a backward-pointing, arrowhead-shaped mark on top of the head; and a yellow belly with rectangular brown markings. It lacks the brown stripe passing through the eyes and along the sides of the head.
  • The western ratsnake (black ratsnake or black snake) is the Great Plains ratsnake's closest relative in Missouri, but only the blotched juveniles could be confused with Great Plains ratsnakes.
Other Common Names
Great Plains Rat Snake
House Snake
Emory's Rat Snake

Adult length: 24 to 36 inches; occasionally to 60 inches.

Where To Find
Great Plains Ratsnake Distribution Map

Occurs in northwestern, western, central, and southern parts of the state; absent from the Bootheel.

Active from late March to October, this species is generally nocturnal, spending daylight hours under rocks, logs, and boards, or in small mammal burrows and rock crevices below ground. In our state, it prefers open woodlands, rocky, wooded hillsides, glades, and caves. In the twilight zone of caves (between full daylight and complete darkness), Great Plains ratsnakes coil up in rock crevices and prey on bats as they exit the cave in the evening.

They overwinter in rodent burrows, rock crevices, caves, hollow old logs and stumps, and rock-lined wells. They sometimes overwinter in caves.

Great Plains ratsnakes hunt in the night for rodents, bats, and small birds. They also sometimes eat frogs, lizards, and small snakes. They subdue larger prey by constriction, but they grab smaller prey with the mouth and swallow them directly.

The Great Plains ratsnake is relatively uncommon in Missouri, but because of its secretive and nocturnal habits, it might be more abundant than presumed.

The life history of this species has not been thoroughly studied in Missouri, nor has it been well studied throughout its overall range.

Life Cycle

Breeding apparently occurs soon after these snakes emerge from their overwintering retreats and probably extends from March through May. Only one clutch, containing 3–37 eggs, is laid per season, usually sometime between late May through July. Hatching takes place in August and September. Individuals become mature at around two or three years of age. Lifespan has been as long as 21 years in captivity.

On a very practical level, snakes help humans by consuming many rodents that are injurious to our interests. This snake is sometimes called the "house snake" because people often encounter it around abandoned farm buildings. In farm buildings, these snakes hunt rodents attracted to grain and shelter.

Psychologically and culturally, snakes have always captured the imaginations of humans. In myth, religion, and story, snakes perform the role of seducer, sneak, guardian, healer, killer, and transformer.

The Great Plains ratsnake used to be classified as Elaphe guttata emoryi, but scientists have since changed its genus and elevated it to a full species: Pantherophis emoryi. It was named in honor of William Hemsley Emory (1811–1887) and is sometimes called "Emory's rat snake." Emory was a topographical engineer and surveyor famous for mapping the southern US border, including the Gadsden Purchase (southern Arizona). In addition to holding numerous federal posts, he served in the Mexican-American War and the Civil War, retiring as a major general. While in the desert Southwest, he made scientifically valuable notes on the natural history of the region.

Snakes use organs in their tongues and mouths to detect odors and track their prey. As nocturnal predators, they must depend on something other than sight to interpret their surroundings. Many mice and other small mammals are active at night, too, and similarly have a well-developed sense of smell.

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Similar Species
About Reptiles and Amphibians in Missouri
Missouri’s herptiles comprise 43 amphibians and 75 reptiles. Amphibians, including salamanders, toads, and frogs, are vertebrate animals that spend at least part of their life cycle in water. They usually have moist skin, lack scales or claws, and are ectothermal (cold-blooded), so they do not produce their own body heat the way birds and mammals do. Reptiles, including turtles, lizards, and snakes, are also vertebrates, and most are ectothermal, but unlike amphibians, reptiles have dry skin with scales, the ones with legs have claws, and they do not have to live part of their lives in water.