Michigan is home to a diverse array of reptiles, supporting a total of 17 native snake species across ecosystems ranging from northern forests to southern wetlands. Only one of these species possesses venom that poses a threat to humans. Most of Michigan’s snakes are non-venomous and play a beneficial role in maintaining the natural balance of their habitats.
Common Non-Venomous Species
The non-venomous snakes are the most frequently encountered in Michigan, and they are generally harmless to people. Among the most common is the Eastern Garter Snake, which is easily recognizable by the three light-colored stripes that run down its dark body, often in shades of yellow or orange. These snakes are relatively small, typically measuring between two and four feet long, and can be found in nearly every habitat, including backyards and garden areas. Garter snakes are active hunters that help control populations of frogs, earthworms, and mice, contributing significantly to local pest control.
Another widespread species is the Eastern Milk Snake, which can be distinguished by a pattern of reddish-brown blotches bordered by black against a light gray or tan background. These snakes, which typically reach two to three feet in length, are often mistaken for the state’s venomous species due to their blotchy appearance. Milk snakes are beneficial predators of small mammals, like shrews and mice, and are even known to consume other snakes. They are secretive and often spend time beneath logs, rocks, or other debris.
The Northern Water Snake is a larger snake that can grow up to four feet long and is often found near lakes, rivers, and marshes. They have dark bands on a brown or reddish-brown body and are frequently seen basking on logs near the water’s edge. Northern Water Snakes eat fish and amphibians and, when disturbed, may aggressively defend themselves by biting, though their bite is not venomous. These species are important components of the ecosystem, primarily as controllers of rodent populations.
Identifying Michigan’s Venomous Snake
Michigan is home to only one venomous snake species: the Eastern Massasauga Rattlesnake (Sistrurus catenatus), often referred to as the “swamp rattler”. This pit viper is a small- to medium-sized snake, with adults typically ranging from 2 to 3 feet in length. The Massasauga is identifiable by its relatively thick, heavy body and a distinct pattern of dark, rounded blotches, often described as bowtie-shaped, set against a gray or grayish-brown background.
The most recognizable feature is the segmented rattle on the end of its tail, which produces a characteristic buzzing sound when the snake feels threatened. Unlike some non-venomous snakes that may vibrate their tails, the Massasauga has a true horny rattle. As a pit viper, it also possesses heat-sensing pits on its head, a vertical, cat-like pupil, and a distinctly triangular head shape, though the latter can be mimicked by non-venomous species when they feel threatened.
This rattlesnake has a limited and specific geographic distribution within the state, primarily concentrated in the Lower Peninsula’s wetland habitats. They are strongly associated with prairie fens, bogs, marshes, and wet meadows, though they will use adjacent upland areas seasonally. Despite its venom, the Eastern Massasauga is a timid and reclusive animal that prefers to hide or remain motionless to avoid detection.
Safety and Legal Protections
Encountering any snake in Michigan should be handled with caution and respect. The most important safety rule is to never attempt to handle, harass, or intentionally provoke any snake, regardless of whether it is venomous or non-venomous. If a snake is encountered, the best action is to observe it from a distance and allow it to move away naturally.
Bites are almost always a result of a person trying to catch, kill, or move the animal. The Eastern Massasauga Rattlesnake is a species of special concern in Michigan and is federally protected as a threatened species under the Endangered Species Act. This legal protection restricts the “take” of the snake, including killing, collecting, harming it, or damaging its habitat. The species has been declining due to habitat loss and fragmentation across its range.