Common garter snakes are frequently encountered reptiles across North America, often leading to questions about their potential danger to humans. Many people are unsure if these snakes, commonly found in gardens and natural areas, are venomous. Understanding their true nature can alleviate misconceptions and promote a more informed coexistence.
The Truth About Garter Snake Toxicity
Common garter snakes are not venomous like vipers or cobras. However, they produce a mild neurotoxin from Duvernoy’s glands, distinct from the highly specialized venom glands. This secretion is in their saliva, not injected through hollow fangs, as garter snakes have small, solid teeth.
The neurotoxin primarily subdues their small prey like amphibians and invertebrates. For humans, a bite typically results in minimal or no reaction. Some individuals might experience mild symptoms like localized itching, slight burning, or minor swelling, but these reactions are rarely severe. Minor bruising has also been reported in rare instances.
It is important to differentiate between “venomous” and “poisonous.” A venomous animal injects toxins, while a poisonous animal contains toxins that are harmful if ingested or absorbed. Garter snakes can be mildly venomous due to their saliva and, in some cases, poisonous if they consume toxic prey like newts and retain those toxins in their liver. Despite these properties, their bite poses little to no risk to humans.
Distinguishing Garter Snakes
Common garter snakes have a slender build, averaging 55 cm (22 inches) but reaching up to 137 cm (54 inches). Their coloration varies, often featuring yellow stripes on a black, brown, or green background. Some subspecies may display blue, yellow, or red stripes, with keeled scales giving them a slightly rough texture.
Widely distributed across North America, from central Canada to Costa Rica, garter snakes are highly adaptable. They inhabit various environments, including forests, woodlands, fields, grasslands, and suburban gardens. Often found near water sources like ponds, streams, and wetlands, amphibians are a significant part of their diet. They are diurnal, active during the day, especially in mornings and late afternoons during warmer seasons.
Encountering a Garter Snake
Garter snakes are timid and non-aggressive. When encountered, their instinct is to flee or hide rather than confront. If disturbed or feeling threatened, they may coil, strike, or release a foul-smelling, musky secretion from glands near their tail as a defense.
If found in a yard or home, leave it undisturbed and allow it to move away on its own. These snakes play a beneficial ecological role, acting as natural pest controllers by preying on slugs, snails, insects, and small rodents, which helps maintain a balanced garden ecosystem.
In the rare event of a garter snake bite, which typically feels like a pinch or mild sting, the symptoms are usually minor. Clean the wound thoroughly with soap and water to prevent infection. Applying an antiseptic ointment after cleaning is also recommended. While serious reactions are uncommon, monitor the bite area for signs of infection, such as increased redness, swelling, or pus, or for rare allergic reactions. If symptoms worsen or cause concern, seek medical attention.