It's no secret that snakes shed their skin. Here, a common garter snake mugs for the camera.
Credit: David Duneau
With a range spanning Alaska to New Mexico, garter snakes are probably the most commonly seen snakes in North America — so the fact that they pose no real threat to humans is good news. Scientists had classified garter snakes as non-venomous, but they do possess a mild neurotoxic venom. However, it is not dangerous to humans.
There are 28 species of garter snakes (genus Thamnophis) and many more subspecies. They are sometimes kept as pets, and the common garter snake is the only snake found in chilly Alaska. The garter snake is the state reptile of Massachusetts.
Where did the garter snake get its funny name? There are two schools of thought. One holds that their stripes resemble garters men used to wear to hold up their socks. The other theory is that it is a corruption of the German word for “garden.” Garter snakes are sometimes erroneously called "garden snakes."
Garter snakes come in a wide variety of colors, but all have a striped pattern over a green or brown body. They have at least two longitudinal stripes, one on their side and one on their back. The stripes run close to the length of their bodies and may be red, yellow, blue, white or orange. Some garter snakes have intricate splotchy patterns between their stripes, making them look checkered.
Garter snakes are relatively small, usually between 23 and 30 inches (58 and 76 centimeters), though sometimes growing as long as 5 feet (1.5 meters).
Garter snakes live in woodlands, meadows, and grassy knolls and like to be near water. They sometimes reside in suburban areas with sufficient moist cover from logs or debris.
Garter snakes are generally active during the day. Some are excellent swimmers. When threatened, garter snakes give off a bad-smelling musk. Because of their small size, garter snakes have many predators, including birds, bears and raccoons.
Cold-climate garter snakes hibernate during the winter. They hibernate in dens in large groups, with hundreds of garter snakes sometimes found together. Garter snakes will travel up to 20 miles to a communal den for hibernation.
Sometimes people collect hibernating garter snakes from their dens and sell them as pets.
Garter snakes are small and will eat most anything they can overpower, including earthworms, slugs, crickets and other insects, frogs, fish, tadpoles, small birds, and small rodents. They kill their prey with their neurotoxic venom, which paralyzes it. They then swallow it whole.
When it is time to mate, female garter snakes give off pheromones to attract males. Dozens of males will come to one female, which is why homeowners sometimes think garter snakes are overrunning their neighborhoods.
After mating, females store sperm in their bodies until they want to fertilize their eggs. They can store sperm for up to 5 years. Garter snakes give birth to 20 to 40 live young at a time. The largest known litter of baby garter snakes had 98 babies. Parent snakes do not care for their young.
Garter snakes have two narrow fangs, but they do not inject their venom through them. Rather, their venom is transferred to the prey through their saliva. Garter snakes spread their venom into the prey’s wounds in a chewing motion.
Their venom is neurotoxic, causing paralysis that makes small prey easier to swallow. It can cause minor swelling or itching in humans, and anyone bitten by a garter snake should clean the bite thoroughly. It is not ultimately a cause for concern. [Fun Facts About Snakes]
Garter snake species
These are just a few of the 28 species of garter snake:
Common Garter Snake
This most typical of garter snake (Thamnophis sirtaris) has the largest dispersion of any snake in North America, found everywhere from Alaska to Florida. It does not live in the Southwest. Common garter snakes usually have three white, yellow, blue, green, or brown stripes running the lengths of their brown or olive bodies. Their heads are darker than their bodies. Their coloring depends on region, however, and there are some groups of entirely black common garter snakes.
Eastern Garter Snake
This subspecies of common garter snake (Thamnophis sirtalis sirtalis) is typical throughout the Eastern US. Though its body color may vary from brown to green, it almost always has three yellowish stripes on its back. Sometimes its body is splotchy, giving it a checked appearance. Eastern garter snakes in Georgia and Florida sometimes have bluish coloring.
Red-Sided Garter Snake
This California subspecies of common garter snake (Thamnophis sirtalis parietalis) can be stunning. Blue or yellow stripes pop against the dark olive or black body, and red bars line the sides of the body. The red-sided garter snake has a red or orange head and a blue underside. North of the Bay Area, the underside is sometimes a brilliant bright blue. Its eyes are larger than other garter snake species. It is able to eat Pacific newts, which are poisonous to other predators.
San Francisco garter snake
This San Francisco peninsula snake (Thamnophis sirtalis tetrataenia) has a red head, big eyes, and wide, blue-green, black, and red stripes. Its underside is blue-green. Like the red-sided garter snake, it eats Pacific newts.
Checkered garter snake
This small, southwestern snake (Thamnophis marcianus) has a dark checkered pattern over its entire body, plus three thin light-colored stripes. It is rarely longer than 2 feet.
Texas garter snake
This common garter snake subspecies (Thamnophis sirtalis annectens) primarily resides in the Lone Star State, though there is a population in Kansas. It has a dark colored back with a bright red stripe down its center and two light-colored stripes on its sides.
- For news and features about snakes, visit our Snakes topic page.