The belief that non-venomous snakes, such as the common garter snake (Thamnophis sirtalis), deter or repel venomous species like the copperhead (Agkistrodon contortrix) is a widely held piece of folklore. Garter snakes are common, slender reptiles often found in yards and gardens across North America. Copperheads are pit vipers responsible for a significant number of venomous snake bites in the United States. This article examines the scientific reality of the relationship between these two species.
Assessing the Relationship: Do Garter Snakes Repel Copperheads?
The direct answer is that there is no scientific evidence to support the claim that garter snakes actively repel copperheads. Garter snakes do not possess any specific pheromone, behavior, or territorial instinct that would drive a copperhead out of an area. In fact, these two species often coexist in the same general habitats across the eastern and central United States. They generally ignore one another, as neither poses a threat or competition to the other.
This common misconception likely arises from the misidentification of harmless snakes or the simple presence of non-venomous species where copperheads are absent. The occasional observation of a garter snake without a copperhead nearby can lead to the false conclusion that the former is actively deterring the latter. Both species are focused on finding prey and shelter, and their paths only cross incidentally.
Distinct Ecological Niches of Both Species
The lack of interaction stems from the specialized ecological roles each snake occupies. Copperheads are heavy-bodied pit vipers that rely on camouflage and an ambush strategy to capture prey. They are often associated with deciduous forests, rocky hillsides, and areas with abundant leaf litter and cover. Garter snakes are highly adaptable and thrive in a wider range of environments, including lawns, fields, wetlands, and suburban gardens.
Their distinct diets minimize any potential for resource conflict. The copperhead primarily preys on small mammals like rodents, amphibians, and large insects such as cicadas. Adult copperheads especially focus on warm-bodied vertebrate prey. Garter snakes, however, are major consumers of soft-bodied invertebrates and amphibians, including earthworms, slugs, snails, leeches, and small fish.
The physical difference means the non-venomous garter snake is not a threat to the copperhead. Copperheads are typically 22 to 36 inches long with a distinct hourglass pattern. Garter snakes are slender, generally 18 to 42 inches long, and have stripes running down their bodies. Garter snakes are not large enough to prey on adult copperheads, and their mildly toxic saliva is only effective on their specific small prey.
Garter Snakes: Role in the Local Ecosystem
While they do not repel copperheads, garter snakes play a beneficial role in local ecosystems. These snakes are highly effective natural pest controllers, especially in garden settings. Their diet, which includes common garden pests like slugs, snails, and earthworms, helps to regulate invertebrate populations. This natural pest control benefits gardeners without the use of chemical treatments.
Garter snakes are diurnal, meaning they are active during the day, making them a common sight. They are non-aggressive and will typically flee or remain motionless when approached, relying on camouflage for defense. They are entirely harmless to humans and pets, posing no risk beyond a potential musk secretion if handled.
Protecting garter snake populations is important for maintaining a healthy ecological balance. Their presence indicates a vibrant local environment and should be welcomed. They are a natural and helpful component of the ecosystem.
Proven Strategies for Managing Copperhead Presence
The most effective way to reduce the likelihood of encountering a copperhead is through habitat modification and exclusion, not by relying on other snake species. Copperheads are attracted to areas that offer shelter and a reliable food source. Eliminating potential hiding spots is the first step in managing their presence around a home.
Habitat Modification
Clearing away piles of debris, such as woodpiles, rock piles, dense brush, and thick leaf litter, removes ideal resting and ambush locations. Any stacked materials like firewood or lumber should be elevated at least 18 inches off the ground and stored away from the house structure. Overgrown landscaping should be trimmed back to reduce ground cover and sunning spots.
Control of the copperhead’s primary food source, rodents, is also a preventative measure. Secure outdoor garbage cans and remove spilled birdseed or pet food to reduce the attraction for mice and rats, which copperheads actively hunt. If a snake is encountered, the safest approach is to leave it alone and contact a professional wildlife control service for safe, non-lethal removal. Most bites occur when people attempt to capture or kill the snake.