Snakes in Wisconsin

Wisconsin has about 10+ species of snakes, and only 2 of them are venomous. The overwhelming majority you might run across are harmless and quietly useful, eating mice, voles, slugs, and insects. Snakes here favor sunny edges, wetlands, and the rocky country of the southwest, and most are quick to retreat when people approach.

The state's landscape ranges from glaciated lake and wetland country across much of the north and east to the rugged, unglaciated Driftless Area in the southwest. The Driftless region, with its limestone bluffs, dry rocky prairies, oak savannas, and river valleys along the Mississippi and Wisconsin rivers, is the heart of the state's snake diversity. Farther north, glaciated lakes, bogs, and conifer forest hold fewer species.

Both of Wisconsin's venomous snakes are rattlesnakes concentrated in the Driftless Area. The Timber Rattlesnake lives on warm, rocky, wooded bluffs and is now uncommon and protected. The Eastern Massasauga is a small, secretive wetland rattlesnake of lowland marshes and river floodplains; it has declined sharply and is endangered in the state. Both are reclusive, prefer to stay hidden, and bites are very rare.

Most snakes Wisconsinites see are harmless. Common garter snakes turn up in nearly every yard and field, bullsnakes (gophersnakes) on the sandy prairies hiss and rattle their tails to bluff like a rattlesnake and are too often killed for it despite being excellent rodent hunters, and fox snakes and watersnakes patrol wetlands and shorelines where they get mistaken for something dangerous. Bites are uncommon and rarely fatal thanks to antivenom, and most happen when people try to handle or kill a snake. Never assume a wild snake is safe to handle, and if a bite happens, call Poison Control at 1-800-222-1222 or 911.