Eastern Massasauga Rattlesnake in Michigan

Michigan's Only Poisonous Snake

Eastern Massasauga Rattlesnake
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Michigan has only one poisonous snake: the Eastern Massasauga (“Big River Mouth”) Rattlesnake. As it turns out, Michigan is its main home. Lest you think it is located only in the wilds of the Upper Peninsula, think again. It is actually found in the Lower Peninsula, including Oakland, Livingston and Washtenaw Counties. In fact, Massasauga have been reported in Seven Lakes State Parks and the Matthaei Botanical Gardens at the University of Michigan.

Habitat and Hibernation

The Massasauga hibernates and doesn't emerge until early May when it hunts for crayfish in and around swampland and marshy areas. Keep in mind, this could include areas around boat launches. In the summer months, it can be found in woods and in prairie grass. That being said, the Massasauga's numbers are dwindling. This is partially due to suburban sprawl taking over the wetland areas.

Bite Risk

While the Massasauga's venom is among the most potent of all rattlesnakes, the amount of venom in injects in a bite is relatively small. In fact, only about 75% of the Massasauga's bites have any venom at all.

While the snake will attempt to protect itself, it is docile and not overly aggressive. Of the one-to-two bites that happen each year in Michigan, most are to a person's hand. Death is extremely rare, and no deaths have been reported in Michigan in over 40 years.

Hiking Precautions

While the Massasauga tends to head the other way when humans are around, hikers should stay on trails, pay attention, and take care when crossing logs – favorite hiding places of the Massasauga. It is also a good idea to wear long pants and/or boots. If you should happen upon a Massasauga in your travels, best leave it alone.


Having an uninvited Massasauga in your yard will probably not be an issue unless you live in a wetland area. If so, you can reduce the likelihood of trespass by eliminating rodents and wood piles in your yard, as well as keeping shrubs and grass trimmed.

If you find a Massasauga in your yard, report it to Michigan's Department of Natural Resources. Chances are it will leave on its own and be gone within 24 hours.

Arguments for Conservation

Love it or hate it, the East Massasauga Rattlesnake is part of Michigan's ecology and food chain, so the decline of its numbers should be of concern. The Massasauga eats mice, shrews and small snakes (usually swallowing them whole). It is eaten by herons, hawks, and eagles.

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