The idea that a non-venomous snake can deter a venomous one is a common curiosity, especially concerning the Eastern Rat Snake and the Copperhead in the Eastern United States. Their relationship is complex, involving opportunistic predation and competition for resources, rather than mutual exclusion. Understanding the specific behaviors of both reptiles provides a clearer answer to whether rat snakes actively keep copperheads away.
Identifying the Eastern Rat Snake
The Eastern Rat Snake is among the longest snakes in North America, commonly reaching three to seven feet. While juveniles are gray with dark blotches, mature snakes are often glossy black with a light-colored belly. This large, non-venomous constrictor is an exceptional climber, scaling trees and buildings while searching for food.
These snakes thrive in wooded areas, farmlands, and suburban communities. Their diet primarily consists of rodents, birds, and eggs, making them effective natural pest controllers. Rat snakes are also known to be ophiophagous, meaning they will opportunistically consume other snakes.
Understanding the Copperhead
The Copperhead is a medium-sized, venomous pit viper, typically two to three feet long. It is recognized by its reddish-tan to pale brown body overlaid with dark, hourglass-shaped crossbands. This pattern provides excellent camouflage, allowing the snake to blend seamlessly with leaf litter.
Copperheads are ambush predators that prefer habitats offering cover, such as wooded hillsides, rocky outcrops, and areas with debris like woodpiles. Unlike many other snake species, Copperheads give birth to live young, producing between four and seventeen offspring per brood. Their preference for cluttered areas often leads to their presence in residential environments.
The Ecological Relationship: Predation and Competition
The idea that rat snakes actively deter copperheads is often confused with the actions of other native species, like the Eastern Kingsnake, which actively hunts pit vipers. However, due to the Rat Snake’s opportunistic nature, it will prey on juvenile copperheads or even adults it can overpower.
The primary interaction between the two species is resource competition, not direct confrontation. Since both Rat Snakes and Copperheads hunt rodents, a healthy constrictor population may indirectly reduce the food available for the pit vipers. This reduction in prey can make the area less attractive to Copperheads, potentially lowering their density.
Ecological studies suggest that the presence of non-venomous predators like the Rat Snake can influence Copperhead behavior. High populations of black snakes may force the venomous snakes into less favorable habitats, impacting their population size and reproductive success. While the Eastern Rat Snake is a beneficial native species, relying on it to fully eliminate or consistently deter Copperheads is an unsound expectation.
Safe Strategies for Snake Management
Managing the habitat around your home is the most effective strategy for coexistence and safety, rather than relying on one snake species to control another. Reducing the availability of shelter and food makes an area unattractive to all snakes, including both Rat Snakes and Copperheads.
Reducing Shelter and Cover
Clearing away debris is the most impactful action, including removing rock piles, old lumber stacks, and general yard clutter. Keeping grass and vegetation well-manicured removes the cover snakes use for hunting and movement. Snakes prefer to travel through areas where they can remain hidden, so a short lawn makes them feel exposed.
Eliminating Food Sources and Entry Points
Manage rodent populations by securing trash cans, clearing spilled birdseed, and avoiding the outdoor storage of pet food. This removes the primary food source for both snake species. Finally, sealing gaps in a home’s foundation or around utility entry points prevents snakes from seeking shelter inside a structure.