The informal term “garden snake” refers to the same group of reptiles scientifically known as garter snakes, belonging to the genus Thamnophis. This moniker likely originated from their frequent presence in residential gardens and yards, where they find suitable habitat and food sources.
Understanding the Names
Garter snakes are part of the family Colubridae. The genus Thamnophis includes approximately 35 recognized species and numerous subspecies, distributed across North and Central America, from Canada to Costa Rica. Their scientific name, Thamnophis, derives from Greek words meaning “bush snake,” reflecting their preferred bushy and grassy environments. The common name “garter snake” is thought to come from the resemblance of their striped patterns to the decorative garters once used to hold up stockings.
How to Identify Garter Snakes
Garter snakes are small to medium-sized, typically ranging from 46 to 130 centimeters (18 to 51 inches) in total length, though some can reach up to 1.5 meters (5 feet). Females are generally larger than males.
Their appearance is highly variable across species and subspecies, but they commonly feature three longitudinal stripes running down their bodies. These stripes are often yellow, white, or green, but can also be blue or red, set against a background color of black, brown, gray, or olive. Some garter snakes may have a checkered pattern of spots between their stripes, while others can be virtually stripeless. Their scales are keeled, meaning they have a raised ridge along their length, and their heads are typically wider than their necks.
Garter snakes are diurnal, meaning they are active during the day, and are often found in moist, grassy environments near water sources like ponds, lakes, and streams. Their diet is carnivorous and diverse, consisting of slugs, earthworms, leeches, amphibians like frogs and newts, small fish, and even small rodents.
Garter Snakes and Your Safety
Garter snakes are generally considered harmless to humans and are not aggressive. They are classified as non-venomous, though recent discoveries indicate they produce a mild neurotoxic venom in their saliva. This venom is primarily used to subdue their small prey and is not potent enough to pose a threat to humans, typically causing only minor swelling or bruising in rare cases. Bites are uncommon and usually occur only if the snake feels threatened or is provoked.
If a garter snake bites, its small teeth rarely break the skin significantly, and the bite is often described as more startling than painful, similar to a bee sting. The main concern from any snake bite is the potential for a mild bacterial infection, so cleaning the wound thoroughly with soap and water is advisable.
As a defense mechanism, garter snakes may coil and strike, or discharge a foul-smelling, musky secretion from glands near their cloaca to deter predators. They might also try to hide their head and flail their tail, or even play dead. If encountered, observing them from a distance is the best approach.