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I saw a strange snake in my yard today and was wondering if it could be a rattlesnake. How can I tell the difference between harmless and dangerous snakes?

The vast majority of snakes are harmless and beneficial. Michigan's only venomous snake has rattles and elliptical (cat-like) pupils in its eyes. Native snakes with pointed tails and round pupils are non-venomous. Of course, almost any wild animal will defend itself if it is threatened, trapped, or grabbed by a presumed predator (such as a human!). 

Remedies to snakes getting into buildings, or where fearful people wish to discourage snakes from living around a home:

  • Image of eastern Massasuga rattlesnakeExclusion: Seal up holes in basement walls and/or foundations. Seal cracks around porches, steps, etc..
  • Change environment: Snakes need cover, food. Seal under decks; trim bushes off ground, keep thick shrubs and mulches away from house foundation. Mow lawn short, and keep thick, natural plantings and wood piles at periphery of yard. Pick up all lumber and debris. Snakes will avoid a "clean" area without protecton from predators.
  • Repellents: Commercial repellents are available for use around houses, but these tend to be effective only in small areas, such as right around a foundation or porch.
  • Capture and removal: Harmless species can be captured with a thick-gloved hand or "swept" into overturned boxes and trash cans with a soft broom and moved to natural habitat. Snake traps are available commercially, but effectiveness is inconsistent. For venomous snakes, it is best to get professional assistance for capturing and removing them.)
  • Killing: (Please don't; many snake species (even formerly common species) are becoming rare and some species are legally protected. The Massasauga Rattlesnake is unlikely to bite unless it is stepped on or directly attacked.)

More Detailed Information

Michigan has only one species of venomous snake‚ÄĒthe Eastern Massasauga Rattlesnake.

Image of eastern Massasuga rattlesnakeThey are found throughout the Lower Peninsula and on Bois Blanc Island. There are no venomous snakes native to the Upper Peninsula mainland. Massasaugas are rare, but might occur anywhere there are marshy or swamp wetlands bordered by undeveloped upland habitats (meadows, old fields, open woodland). They use the wetlands from fall through spring, and often move to drier habitats in summer.

All other native Michigan snakes (17 species) are non-venomous, and basically harmless to humans if not handled or harmed. (Almost any animal, from chipmunks to chickadees, can bite in self-defense!)

The quickest way to tell a rattlesnake from any other native snake is to look at the tail tip for rattles (any Michigan snake with a sharp, pointed tail tip is not venomous). Occasionally a harmless snake will lose its tail tip to a predator, but a rattler will never have a sharply pointed tail, even if rattles break off. Also, rattlers have cat-like eyes in bright light, while all other native snakes have round pupils. You can see feature this even from several feet away!

Image of northern water snakeThe most common snakes in Michigan are the harmless garter and ribbon snakes, which almost always have lengthwise, light-colored stripes running down the back. Many people recognize "striped" snakes as harmless, but are more suspicious when they see a snake with a blotchy pattern on the back. Two common "blotchy" snakes of southern Michigan are the Northern Water Snake and the Eastern Milk Snake. Water Snakes are found along river and lake edges, while Milk Snakes often inhabit upland woods and farming areas, and often turn up in suburban yards. Because Milk Snakes will often vibrate their tails when threatened, they are surely the one harmless species most often confused with the rattlesnake.

The differences between a Milk Snake and a Massasauga would be quite clear if you saw the actual animals side by side. The Milk Snake has a narrow body, with a neck not much smaller than the body, and a smallish narrow head. The pupils in the eyes are round in daylight. The tail tapers to a point. The blotches down the back are usually reddish brown, bordered by black, on a tan or gray background.

The also harmless but more rare Eastern Hog-nosed Snake might also be confused with a rattlesnake.¬† They have a turned-up snout, round eye pupils, and pointed tails.¬† When threatened, they spread out their necks and heads (cobra-like) and may hiss and writhe around and try to look fierce, but it's all a bluff‚ÄĒ they are harmless to people.¬† When greatly stressed, they may even flip over and "play dead!"

Image of eastern hog-nosed snakeThe Massasauga, on the other hand, has a chunky body contrasting with a very narrow neck and a wider head. The heat-sensing "pits" are visible between the eyes and nostrils. The pupils are vertical (cat-like) in daylight. The tail ends in a small segmented rattle. The blotches are dark brown or dark gray, bordered by black, on a grayish or gray-brown background (though some rattlers are very dark with an obscured pattern).

Massasauga populations are declining due to persecution and habitat loss, and are a protected species in Michigan. The Michigan Department of Natural Resources is surveying previously known and potential massasauga habitats across the state to see where they still exist. These little rattlers are not considered deadly to humans, but bites are painful and can cause complications. Simply leaving the snakes alone is the best defense‚ÄĒthey are usually very shy don't want confrontation with humans.

For descriptions of these and other Michigan snakes, check out our "Critter Field Guide"


Image of Butlers garter snakeJames Harding
MSU Museum
Michigan State University
East Lansing, MI 48824
(517) 353-7978