Illinois is world-famous for snakes.

On March 15, Snake Road in southern Illinois closes to vehicles as it does every year so migrating reptiles and amphibians can safely cross.

Why’d the snake cross the Illinois road?

Christopher Evans

As someone who works in conservation, the phrase “the only good snake is a dead snake” is one I have heard a lot. I’ve found this sentiment and the fear fueling it comes from a lack of knowledge about the native snakes we share our woods, trails and waterways with.

Illinois is home to 40 species of snakes, including 11 listed as state endangered or threatened.

Snakes are solitary predators. Like other reptiles, snakes are cold-blooded and do not produce body heat internally. Instead, their body temperature varies with their environment. They bask in the sun or lay on warm rocks or soil, particularly early in the spring or during cool mornings or evenings.

As temperatures drop in the fall, snakes search for a protected place to overwinter. This is often in loose rock piles, fissures in cliffs or rock outcroppings, rodent burrows or decaying tree roots.

Technically, snakes do not truly hibernate. Instead, they go through brumation.

Hibernating animals go into a deep sleep the entire duration, but animals that go through brumation do not. Snakes may take advantage of warm spells in winter to emerge from their winter den to bask or get a drink. Sometimes, snakes travel quite a distance to find a suitable hibernaculum, or shelter.

Snake Road migration

Snake Road is famous for the migration phenomenon. Snake Road in LaRue-Pine Hills Research Natural Area splits LaRue Swamp and the base of towering chert bluffs of the Pine Hills.

Every spring and fall, reptiles and amphibians cross this road to travel between the summer swamp habitat and winter hibernation sites in the bluffs.

So many animals cross – 23 snake species have been observed – that Shawnee National Forest managers close it to vehicle traffic from March 15 to May 15 and Sept. 1 to Oct. 30. The road is open to foot traffic, and many snake enthusiasts hike it during the migration.

Common snakes of Illinois

Here are some common snakes in our state.

Small species are seldom seen because they spend most of their life underground or in leaf litter. Turn over your garden soil or rake up forest leaves and you might spot the Dekay’s snake, a worm snake or a smooth earth snake.

Water snakes are encountered if you spend any time on Illinois lakes, rivers or ponds. These include a plain-bellied water snake, diamond-backed water snake or northern water snake.

Common garter snakes are found in every county in yards, empty lots, forests, grasslands and everywhere in between.

Venomous snakes of Illinois

Venomous snakes are rare in Illinois and becoming more uncommon with habitat loss.

Timber rattlesnakes are considered a threatened species and occur in moderate numbers only in the Shawnee Hills.

Eastern massasauga rattlesnake, an endangered species, previously was common in the northern two-thirds of the state. Now, Clinton County is home to the only population thought large enough to survive the next 20 years.

Eastern copperheads are found only in the southern two-thirds of the state.

Cottonmouths are water snakes found only in the southern tip of Illinois.

If you see a snake, be excited to have experienced such a cool animal sighting and take a picture if you can. After that, leave it be! Do not harass, try to move the snake or kill it. Reptiles and amphibians are protected under state law. Plus, it is illegal to kill or collect them on public land without a permit.

Illinois snakes are not aggressive toward people and will not chase you. Bites are incredibly rare and almost always occur as a defensive act when the snake was threatened by humans.

Snakes can be very beneficial around your house because they can help reduce rodent or insect pest populations.

If you are interested in promoting snakes on your land, there are landscaping steps to enhance their habitat.

If you can’t get over your fear or would rather not be startled by them around the house, try some practices to discourage their presence.

Visit Illinois Department of Natural Resources at {wildlifeillinois.org/wp-content/uploads/2019/01/SNAKES-OF-ILLINOIS-2019.pdf} for information, or your local Extension staff can connect you with a herpetologist.

Christopher Evans serves as a University of Illinois Extension forestry and research specialist and interim state coordinator of the Master Naturalist Program.