Types of garter snakes

Thamnophis is a genus of small to medium New World colubrids known as the garter and ribbon snakes. The name comes from the long light stripes that run the length of the body, which reminded early observers of the striped garters once used to hold up stockings. Most species are slender and carry three pale stripes set against a darker background, one running down the spine and one along each side, though the exact pattern and color vary widely between species and even between individuals.

These are the most widespread and commonly encountered snakes across much of North America, and for many people they are the first wild snake they ever see. The genus ranges all the way from Canada south through the United States and into Central America, and individual species turn up in backyards, gardens, parks, and especially in damp ground near ponds, streams, and wetlands. If you spot a slender striped snake gliding through grass or basking near water, a garter snake is the most likely answer.

An accurate nuance is worth getting right. Garter snakes have long been called harmless, and they are harmless in any practical sense, but they are technically rear-fanged and produce a mild saliva toxin. A bite from a large individual can in rare cases cause minor local swelling. They are not dangerous to people, and the database lists all 35 Thamnophis species here as non-dangerous. The realistic risk from a garter snake is a small scratch and a bad smell, not envenomation.

Ecologically these snakes are generalist hunters of soft-bodied and aquatic prey. They eat earthworms, slugs, amphibians, and fish, and some populations have evolved a striking tolerance for the toxins of newts that would sicken other predators. Garter snakes give birth to live young in large litters rather than laying eggs, and in places such as Manitoba they famously gather into enormous mating balls in spring, with many males coiling around a single female as they emerge from communal dens.

For safety the message is simple. Garter snakes are harmless, beneficial residents that help keep slugs and other garden pests in check, so the best response to finding one is to leave it alone and let it move on. If grabbed they often release a strong musky smell from glands near the tail as a defense, which is unpleasant but does no harm. As with any wild snake, observing without handling is the right call.