31 Types of SNAKES That Live in Illinois! (ID Guide)
There are A LOT of snakes in Illinois!
And what’s interesting is that they are all incredibly unique and have adapted to fill many habitats and niches.
You’ll see that the snakes that live in Illinois are very different from each other.
For example, some species are venomous, while others use constriction to immobilize their prey. Or the fact that certain snakes are rarely seen because they spend most of their time underground, but others are comfortable living EXTREMELY close to humans.
31 types of snakes in Illinois!
#1. Eastern Copperhead
- Agkistrodon contortrix
Identifying Characteristics:
- Adults reach lengths between 20 and 37 inches.
- Stout body, broad head, and elliptical pupils.
- Coloration varies from pale tan to pinkish-tan with darker, splotchy, hourglass-shaped bands, which are darker at the edges.
Look for these VENOMOUS snakes in southern Illinois in deciduous forests and mixed woodlands, often near rocky outcroppings. You’re more likely to see them active during the day in the spring and fall when the weather is cooler. During the middle of summer, Eastern Copperheads are often nocturnal.
Eastern Copperhead Range Map
Credit: Virginia Herpetological Society
This species is an ambush hunter, meaning that it selects a suitable site and waits to surprise its prey. In addition, copperheads are considered “pit vipers,” which means they have a heat-sensing organ located between their eyes. This adaptation helps these venomous snakes find and judge the size of their prey by being able to sense infrared!
Bites from these snakes are rarely fatal in Illinois.
The venom they produce has relatively low potency. In addition, copperheads also frequently employ false strikes, dry bites, and warning bites. Dry bites contain no venom, and warning bites have a relatively small amount of venom.
These snakes primarily feed on small rodents, frogs, birds, and large insects such as cicadas. After the initial bite, they will wait for the venom to take effect before consuming their prey whole.
#2. Timber Rattlesnake
- Crotalus horridus
Identifying Characteristics:
- Adults typically range from 30 to 60 inches in length.
- Coloration is variable and generally ranges from yellowish-brown to gray to almost black. Look for dark brown or black crossbands on their back.
- Heavy-bodied with characteristic rattle on the tail.
The Timber Rattlesnake, also known as the Canebrake Rattlesnake, is found in a wide variety of habitats in Illinois. Look for these venomous snakes in lowland thickets, high areas around rivers and flood plains, agricultural areas, deciduous forests, and coniferous forests.
Timber Rattlesnake Range Map
Credit: Virginia Herpetological Society
These snakes are ambush predators, waiting for unsuspecting prey to come within range of their strike. They feed primarily on small mammals but may also consume frogs, birds, and other smaller snakes. Timber Rattlesnakes strike their prey and release them, waiting until their venom has taken effect before eating them.
These venomous snakes are potentially the most dangerous species found in Illinois due to their large size, long fangs, and high venom yield. Luckily, Timber Rattlesnakes have a mild disposition and don’t bite often. They typically give plenty of warning by rattling and posturing.
The Timber Rattlesnake played a noteworthy role in U.S. history. Found in the original 13 colonies, it was used as a symbol during the American Revolution. In 1775 it was featured at the center of the “Gadsden Flag.” This yellow flag depicts a coiled and ready-to-strike Timber Rattlesnake and the words “Don’t Tread on Me.”
#3. Eastern Massasauga
- Sistrurus catenatus
Identifying Characteristics:
- Adults are typically around 2 feet in length.
- Coloration is gray or light brown with darker chocolate-brown blotches on the back and smaller ones on the sides, which feature light edges.
- Thick body, vertical pupils, heat-sensing pits between the eyes and nostrils, and heart-shaped head.
- Being rattlesnakes, look for the rattle at the end of their tail.
These small venomous snakes live primarily in wet habitats in Illinois.
The name “Massasauga” actually comes from the Chippewa language and means “great river mouth” which describes their habitat. Look for them in floodplain forests, shrub swamps, low areas along rivers and lakes, wet prairies, moist grasslands, bogs, and marshes. During the summer, they often migrate to drier regions adjacent to these habitats.
Eastern Massasauga Range Map
Unlike other rattlesnakes, the Eastern Massasauga hibernates alone. They frequently hibernate in crayfish burrows but may also use small mammal burrows or spaces under rotting logs or tree roots. Dens must be below the frost line, or they risk freezing to death!
These snakes have cytotoxic venom (poisonous to cells), which destroys tissue, disrupts blood flow, and prevents clotting. But these snakes are secretive, shy, and avoid humans when possible. The only times they bite seem to be when handled or accidentally stepped on!
This venomous snake is listed as threatened, endangered, or a species of concern in all of its range. Historically, these snakes have faced pressure from hunting, and many states had bounties and roundups for them. Today they are still often killed out of fear AND face diminishing wetland habitats.
#4. Common Water Snake
- Nerodia sipedon
There are two subspecies of the Common Water Snake in Illinois.
Their coloration varies depending on which one you see!
-
Northern Water Snake (N. s. sipedon):
- Coloration is pale grey to dark brown with reddish-brown to black bands.
- Large adults become darker with age and appear almost plain black or dark brown.
-
Midland Water Snake (N. s. pleuralis):
- Typically light gray in color, but some individuals are reddish.
- Near the head, they have dark crossbands. As you move down the snake, the crossbands are replaced by dark squarish blotches.
Common Water Snakes prefer slow-moving or standing water such as ponds, lakes, vernal pools, marshes, and slow-moving rivers and streams. They’re most often seen basking on rocks or logs in or near the water.
Common Water Snake Range Map
Credit: Virginia Herpetological Society
When disturbed, Common Watersnakes flee into the water to escape. However, if grabbed or captured, they’re quick to defend themselves. They will release a foul-smelling musk from glands near the base of their tale, flatten their body, and strike the attacker.
While non-venomous, they can deliver a painful bite!
Their saliva contains a mild anticoagulant that can cause bites to bleed, making the injury appear worse. These important defense mechanisms help water snakes survive predators such as raccoons, snapping turtles, foxes, opossums, other snakes, and birds of prey.
Common Water Snake populations are considered to be stable in Illinois. However, like many other water snakes, this species faces habitat loss and degradation. Unfortunately, they are also commonly killed by people out of fear.
#5. Plain-bellied Watersnake
- Nerodia erythrogaster
Identifying Characteristics:
- Adults have thick bodies and range from 24 to 40 inches in length.
- Solid coloration of gray, brown, olive, or black.
- As the name suggests, they have a plain unmarked underside varying from red to yellow.
- Also called Redbelly, Yellowbelly, Copperbelly, or Blotched Watersnake.
The Plain-bellied Watersnake can be found near various water sources, including rivers, floodplains, lakes, ponds, and wetlands. This species spends an unusual amount of time on land compared with other water snakes found in Illinois. Especially during hot, humid weather, they can be found in woodlands quite far from a water source.
Plain-bellied Watersnake Range Map
Credit: Virginia Herpetological Society
They feed on BOTH aquatic and terrestrial prey, including crayfish, fish, salamanders, frogs, and other amphibians. Another unusual feature of this species is that they will sit and wait to ambush their prey, especially on land. Almost all other water snakes actively hunt and chase their victims!
If captured, they release a foul-smelling musk and are not afraid to bite! Plain-bellied Watersnakes are eaten by largemouth bass, egrets, hawks, and sometimes other larger snakes.
#6. Queen Snake
-
Regina septemvittata
Identifying Characteristics:
- Adults are generally around 24 inches in length though individuals up to 36 inches have been reported.
- Coloration is drab brown or olive green with two lighter stripes down the sides.
- The underside is yellow or tan, with four dark stripes that run the length of their belly. No other similar species has this feature!
Queen Snakes prefer moving water and are generally found near streams and rivers with rocky bottoms. They have highly permeable skin, making them susceptible to evaporative water loss. As you can imagine, they are rarely spotted far from water.
Queen Snake Range Map
Credit: Virginia Herpetological Society
Queen Snakes are considered less secretive than many other snakes in Illinois.
They are primarily diurnal and can be spotted basking on rocks, overhanging branches, or vegetation near the water’s edge. They often take refuge under rocks along the edges of streams. If you’re lucky, you may see them swimming.
Queen Snakes are specialist predators that primarily feed on crayfish. They almost exclusively prey on newly molted crayfish, which have soft bodies and can’t use their pinchers yet. They hunt by probing under rocks and other submerged objects for crayfish.
#7. Northern Cottonmouth
- Agkistrodon piscivorus
Identifying Characteristics:
- Adults range from 26 to 35 inches in length. Females are typically smaller than males.
- Most individuals are dark gray to black with a broad head, heat-sensing pits between the eyes and nostrils, elliptical pupils, and a blunt snout.
- Some individuals have a brown, gray, tan, or blackish coloration.
- Also commonly called Water Moccasins, Black Moccasins, or Gapers.
Cottonmouths are the ONLY venomous water snake in Illinois.
Be on the lookout for these snakes in the southern part of the state near swamps, marshes, ponds, and slow-moving streams and rivers, as well as flooded fields and drainage ditches. But they aren’t limited to just aquatic habitats. Cottonmouths can also be found in pine forests, dune areas, and prairies.
Northern Cottonmouth Range Map
Credit: Virginia Herpetological Society
These water snakes have several defensive tactics to warn potential threats to stay away! They often vibrate their tail in the leaf litter, pull their heads up and back, and then open their mouth to hiss and expose a white interior. This particular display is what earned them the name “cottonmouth.“
Since they are venomous, please use extra caution if you come across an unknown water snake. Quite a few species look similar, especially if you just get a glance as one moves across the water.
Luckily, receiving a bite from a Northern Cottonmouth is rare. But when it does happen, it’s very serious as their venom destroys tissue. It is rare to die from their bite, but it does cause swelling and bruising and can leave scars.
#8. Diamond-backed Watersnake
- Nerodia rhombifer
Identifying Characteristics:
- Adults range from 30 to 48 inches in length.
- Coloration is brown, dark brown, yellowish, or olive green. Look for a dark chain-like pattern down the back.
- Thick body with a yellow belly that has dark half-moons.
The Diamond-backed Watersnake can be found in Illinois in a variety of freshwater habitats. They generally prefer slow-moving bodies of water with overhanging vegetation such as ponds, swamps, slow rivers, and streams.
These snakes are common in their range and can be spotted on overhanging branches looking for prey, which mainly include frogs and fish. Once they grab their target, they haul it to shore and wait for it to die before consuming it. This behavior is unique as most other water snakes consume their prey alive.
Diamond-backed Watersnake Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
When disturbed, Diamond-backed Watersnakes will quickly flee into the water and dive below the surface to swim away. If captured, they will bite and release a foul-smelling musk from glands near the base of their tail.
They are relatively common and aren’t considered a threatened species. Unfortunately, they are sometimes killed out of ignorance. People often mistake them for venomous cottonmouths and rattlesnakes.
#9. Graham’s Crayfish Snake
- Regina grahamii
Identifying Characteristics:
- Adults range from 18 to 28 inches in length.
- Coloration is a dull brown, yellowish-brown, or gray.
- Look for yellowish-tan stripes down the sides and sometimes a faint tan stripe down the middle of the back.
This water snake is rather reclusive and hard to find in Illinois.
Look for Graham’s Crayfish Snakes in slow-moving bodies of water such as ponds, prairie streams, marshes, and roadside ditches. They prefer areas with abundant vegetation, rocks, logs, and other debris along the water’s edge, which allows them to hide from predators. They are commonly seen basking on branches overhanging the water.
Graham’s Crayfish Snake Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
As the name suggests, Graham’s Crayfish Snakes primarily feed on crayfish. They hunt exclusively for individuals that recently molted and temporarily have soft bodies. However, they’ll also prey on fish and amphibians, including tadpoles and frogs.
Like many other water snakes, this species is often mistaken for cottonmouths and killed, even though they are MUCH smaller.
#10. Eastern Garter Snake
- Thamnophis sirtalis sirtalis
Identifying Characteristics:
- Adults typically range from 18 to 26 inches in length.
- Coloration varies and can be mixtures of green, brown, or black. Look for a distinct yellow or whitish stripe down the center of their back.
- Some individuals may exhibit a checkered body pattern.
- Subspecies of the Common Garter Snake.
Eastern Garter Snakes are common and easy to locate in Illinois!
In fact, they are typically the snake species that people come across the most. They’re well-adapted to living around people and can often be found in city parks, farmland, cemeteries, and suburban lawns and gardens. Though not required, they prefer grassy environments near freshwater sources such as ponds, lakes, ditches, and streams.
Look for these snakes in Illinois basking in the sun in grassy areas near cover.
Eastern Garter Snakes protect themselves when they are cornered or feel threatened. For example, if you capture or continually disturb one, it will defecate and release a foul-smelling musk from its glands. It’s also common for them to bite as a last resort!
The Eastern Garter Snake most commonly preys on toads, frogs, slugs, salamanders, fish, and worms. However, they are very opportunistic and will eat other insects and small animals they can overpower. They’re active during both the day and night, depending on the temperature.
#11. Western Ribbon Snake
- Thamnophis proximus
Identifying Characteristics:
- Adults range from 17 to 50 inches in length. A slender snake with a long tail!
- Coloration is blackish, brown, or olive with three light-colored stripes; one down the back and one down each side.
- The sides and top of the head are dark, and the upper lip is whitish.
Did you see a slender snake in western Illinois with a long tail?
If so, it was probably a Western Ribbon Snake! This semi-aquatic species is rarely found far from a water source. They typically occupy brush-heavy areas around streams, lakes, ponds, and other water bodies. You may also spot them basking on rocks, flat vegetation, and dry sandy areas near water.
The Western Ribbon Snake has an incredible, unique hunting technique. As they move over land, they make quick, light thrusts of their head and upper body in different directions in sequences of three. It’s similar to a strike, but with their mouth closed. This action disturbs resting frogs, which alerts the garter snake to their location. From there, this snake uses its superior speed to catch its prey.
When they feel threatened, they flee into the water or hide in thick brush. Their coloration provides superb camouflage in dense, brushier areas. If grabbed, Western Ribbon Snakes rarely bite but will thrash around, defecate, and release musk from their anal glands. This species can also shed its tail to escape, but unfortunately, it doesn’t regenerate like some lizard species.
#12. Eastern Ribbon Snake
- Thamnophis saurita
Identifying Characteristics:
- Adults typically range from 18 to 26 inches in length. A slender snake with a long tail!
- Coloration is brown to nearly black with three bright yellow to cream stripes; one down the back and one down each side.
- Snout and entire head are brownish, lips and underneath head are white.
Did you see a slender snake in southeast Illinois with a long tail?
If so, it was probably an Eastern Ribbon Snake!
This species is semi-aquatic and RARELY found far from a source of water. Look for them in a wide variety of habitats, including marshes, grassy floodplains, streams, ditches with grass, wet areas in meadows, and woodlands adjacent to wetlands. Ribbon snakes are even found in suburban areas that match these conditions.
You might spot these snakes basking on branches of trees, bushes, or grasses overhanging the water. They typically hunt in the water and prey on amphibians, fish, and invertebrates.
When disturbed, these snakes quickly flee into grass or brushy areas. If caught, they are not aggressive and rarely bite. But you can expect them to defecate and spray musk onto your hands. In the wild, Eastern Ribbon Snakes rely on blending into their surroundings to escape predators.
#13. Plains Garter Snake
- Thamnophis radix
Identifying Characteristics:
- Adults average 36 inches in length.
- Coloration is gray-green with a distinctive orange stripe down the back and a greenish-yellow stripe down each side.
- Distinct light yellow spots on the very top of the head!
Plains Garter Snakes are almost always found in Illinois in prairies and grasslands near freshwater sources. They have a fairly large population and adapt well to human-modified landscapes. You may spot them near abandoned buildings, trash heaps, or vacant lots.
This species is considered one of the most cold-tolerant of all snakes! In fact, they will even come out of hibernation on warmer winter days.
Plains Garter Snakes feed primarily on earthworms, slugs, and small amphibians. However, they have also been observed preying on small mammals and birds, including the Eastern Meadowlark and Bank Swallow.
#14. Eastern Milksnake
- Lampropeltis triangulum triangulum
Identifying Characteristics:
- Adults typically range from 24 to 36 inches in length.
- Coloration is tan or gray with 3 to 5 rows of reddish-brown, black-edged blotches.
- Look for a gray or tan Y- or V-shaped mark near the rear of the head.
Eastern Milksnakes get their unique name from an old myth that they milked cows since they’re commonly found in barns! Obviously, this isn’t true. Instead, their presence inside barns is likely due to the high number of mice, some of their favorite prey.
Eastern Milksnake Range Map
A member of the kingsnake family, Eastern Milksnakes occupy a wide variety of habitats in Illinois, including fields, woodlands, agricultural areas, and rocky outcrops. These beautiful snakes are somewhat secretive and spend much of their time beneath the ground. You may be able to find one underneath rocks, logs, boards, and other debris.
The Eastern Milksnake prefers to feed on small mammals such as mice and shrews. However, they’ll also consume various types of prey, including birds and bird eggs, lizards, snakes, amphibians, fish, earthworms, slugs, insects, and carrion.
Like other individuals in the kingsnake family, they will prey on venomous pit vipers. So how do they combat the venom? Interestingly, their blood contains venom-neutralizing properties!
#15. Prairie Kingsnake
- Lampropeltis calligaster calligaster
Identifying Characteristics:
- Adults range from 30 to 40 inches in length.
- Coloration is typically gray or light brown with darker gray, brown, or reddish-brown blotching, sometimes outlined in black, down the length of their body that fades with age.
- They have a pale or yellowish underside, and their head is indistinct from their body.
- The Prairie Kingsnake is a subspecies of the Yellow-bellied Kingsnake.
Look for Prairie Kingsnakes in Illinois in open habitats, such as fields, farmland, rocky hillsides, and open woodlands. They spend most of their time underground and are found under rocks, logs, and old animal burrows throughout their active period and winter hibernation.
Prairie Kingsnake Range Map
These snakes feed on a wide variety of prey, like mice, lizards, other snakes (including other Prairie Kingsnakes), insects, birds, bird eggs, and amphibians. They constrict their prey, coiling around and suffocating it before consuming.
If disturbed, the Prairie Kingsnake may try to warn perceived threats by mimicking a rattlesnake. They accomplish this mimicry by shaking the tip of their tail in dry leaf litter. However, these snakes are non-venomous and don’t typically bite, but they will release a foul-smelling musk if grabbed!
This species is considered of least concern and doesn’t seem to face any significant conservation risks. However, they’re sometimes run over when crossing roads or killed because they are mistaken for being venomous. Like many other kingsnakes, this species is sometimes kept as pets.
#16. Eastern Black Kingsnake
- Lampropeltis nigra
Identifying Characteristics:
- Adults typically range from 35 to 48 inches in length.
- Coloration is black with white, cream, or yellow speckles, larger and more numerous on the sides.
- Stocky body, head indistinct from the neck, and a yellow or cream underside with black checkering.
- Also frequently referred to as just “Black Kingsnake.”
Eastern Black Kingsnakes occupy various habitats in southern Illinois.
They can be found in forests, agricultural lands, thick brush around streams and swamps, floodplain and wetland edges, and even suburban areas!
Eastern Black Kingsnake Range Map
These snakes are very secretive, and they often seek shelter under logs and other debris. They’re primarily active during the daytime but are most active in the morning during the summer.
Being constrictors, Eastern Black Kingsnakes use their strong coils to asphyxiate their prey. They frequently prey on lizards, rodents, birds, turtle eggs, and other snakes, including venomous pit vipers.
Though they’re non-venomous, these snakes may shake their tails if disturbed. In dry leaves, the noise sounds like a rattlesnake! If handled, they may also release a foul-smelling musk and strike.
#17. Gray Ratsnake
- Pantherophis spiloides
Identifying Characteristics:
- Adults range from 42 to 72 inches in length though individuals up to 101 inches have been recorded.
- Coloration varies. Most Gray Ratsnakes are typically completely black.
- There may be red, white, or yellow flecking on the scales.
Look for Gray Ratsnakes in Illinois in trees!
They are excellent climbers and often hunt and spend time in trees. Growing up, I used to see them all the time in a large walnut tree in our backyard! They occupy various habitats, including pinelands, stream banks, swamps, marshes, prairies, and agricultural areas.
They’re also spotted near barns and old buildings since these places provide them access to their favorite food, which is rodents.
Like other rat snakes, this species is an active hunter and a powerful constrictor. Adults typically feed on small mammals, birds, bird eggs, lizards, and frogs. They suffocate larger prey using their strong coils but often swallow smaller prey immediately.
If disturbed, Gray Ratsnakes either flee for cover or remain motionless in an attempt to avoid detection using their excellent camouflage. They may also vibrate their tail, producing a rattlesnake-like sound in dry leaf litter. Finally, when they feel cornered or are grabbed, these snakes will strike their attacker as a last resort.
#18. Rough Greensnake
- Opheodrys aestivus
Identifying Characteristics:
- Adults typically range from 22 to 36 inches in length.
- Coloration is bright green with a yellow or whitish underside.
- SLENDER bodies and large eyes.
- Also commonly called a Grass Snake.
This species is hard to mistake for any other snake in southern Illinois!
Their bright green color makes for excellent camouflage against the foliage. They’re highly arboreal and spend much of their time climbing in low vegetation. Look for them coiled and sleeping in shrubs, tangles of vines, or other thick vegetation, especially if it’s near water.
When disturbed, Rough Greensnakes typically freeze and rely on their camouflage. They’re nonvenomous and generally very docile, seldom striking even if grabbed.
The Rough Greensnake is fairly common, but they do face several threats. They’re one of the most exploited pet snake species in North America. They’re also often killed on roads and face habitat loss, especially when small waterways are cleared of vegetation in developing areas.
#19. Smooth Greensnake
- Opheodrys vernalis
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Identifying Characteristics:
- Adults are SLENDER and typically range from 14 to 20 inches in length.
- Coloration is uniformly light green with a yellow or white underside and a red tongue with a black tip.
- Juveniles may be olive-green, blue-gray, or even brown until they shed their skin for the first time.
Also called Grass Snakes, these bright green snakes can be found in northern Illinois in marshes, meadows, pastures, savannas, open woods, and along stream and lake edges. They prefer moist areas near permanent water sources.
They prey almost exclusively on insects and spiders and don’t use constriction; instead quickly striking and swallowing their prey alive.
Smooth Greensnakes hibernate during the winter in Illinois, seeking shelter in old mammal burrows and abandoned anthills. They often hibernate communally with other small snakes. They emerge in the spring, typically in April, and are active until October.
Smooth Greensnakes rely on their EXCELLENT camouflage to avoid predators. They’re also agile and can flee quickly if they must.
#20. Bullsnake
- Pituophis catenifer sayi
Identifying Characteristics:
- Adults are large and typically range from 4 to 6 feet in length.
- Coloration is yellow, beige, or light brown with large brown, black, or reddish blotching on the back and three sets of small blotches on the sides.
- Blotches may appear like bands near the end of the tail, and the underside is yellowish with black spots.
Bullsnakes are often seen in Illinois in areas with high rodent populations.
You can find them in fields, grasslands, forest edges, savannas, and brushlands with sandy soils.
Bullsnakes are fast and can actively pursue prey in loose soil. They even use their prominent rostral (nose scale) to dig! Once they’ve captured their prey, they use their strong body to coil around and constrict their prey.
Despite being nonvenomous, these snakes act aggressively toward any threats. They often lift the front half of their body, hiss, and lunge at their attacker until they feel they can retreat.
Interestingly, their hissing can sound like a rattle! (see below!)
To accomplish this, the snake forces air through an extension of the windpipe, which has a piece of cartilage called an epiglottis that flaps back and forth, sounding very similar to a rattlesnake.
#21. Red-bellied Mudsnake
-
Farancia abacura
Identifying Characteristics:
- Adults range from 40 to 54 inches in length.
- Coloration is smooth, glossy black with a red and black checkered underside with the red extending up the sides, creating a triangle pattern.
- The chin is heavily marked with black and usually yellow, creating a “zipper-like” appearance.
These semi-aquatic snakes are usually found in Illinois near stagnant muddy waters of shallow streams, rivers, drainage ditches, canals, lakes, marshes, and swamps. They’re often spotted under water-soaked logs or other wet, organic debris and prefer habitats with dense vegetation and muddy bottoms and banks.
Red-bellied Mudsnakes are specialized hunters! Adult snakes feed almost exclusively on fully aquatic salamanders. They prey primarily on only two species, the Three-toed Amphiuma and the Lesser Siren.
These docile snakes don’t strike when disturbed or captured. Instead, if grabbed, they may press their harmless, blunt tail tip against their attacker, a behavior which has earned them the nicknames “horn snakes” and “stinging snakes” If continually handled, Red-bellied Mudsnakes may release a foul-smelling musk and go limp or play dead.
This species is incredibly secretive, and its status is poorly known in many areas.
#22. Plains Hog-nosed Snake
- Heterodon nasicus
Identifying Characteristics:
- Adults range from 15 to 39 inches in length.
- Coloration is varying shades of brown with darker brown blotches on the back, two alternating rows of smaller dark spots down the sides, and large longitudinal blotches on the sides of the neck.
- Enlarged rostral (nose) scale.
The Plains Hog-nosed Snake strongly prefers open sandy or gravelly habitats. They’re excellent burrowers and also use old animal burrows for hibernation and protection from hot temperatures.
These snakes are best-known for their impressive displays when disturbed!
When initially confronted, Plains Hog-nosed Snakes typically remain motionless or hide their head under their coils. They may also try to bury themselves or escape into a burrow.
However, if they’re further disturbed, they’ll spread their jaws and neck like a cobra and puff up their bodies. They may also hiss loudly and deliver false strikes with a closed mouth.
If these intimidating displays fail, the Plains Hog-nosed Snake will then twist as though they’re in pain, roll over on their back and play dead. They’ll be limp, open mouthed, and will remain this way even if picked up. They may also bleed from the mouth and cloaca, expel musk and fecal matter, and regurgitate recently eaten food.
If I saw one of these snakes do this display, I’d definitely leave it alone! But, unfortunately, they’re sometimes killed by people who are frightened by their cobra-like posture.
#23. Eastern Hog-nosed Snake
- Heterodon platirhinos
Identifying Characteristics:
- Adults typically range from 20 to 30 inches in length.
- Coloration can be yellow, gray, brown, black, olive, or orange, often with darker blotches or spots down its side and back, though solid gray and black individuals are fairly common.
- Thick-bodied, broad, triangle-shaped heads, and an upturned snout.
Eastern Hog-nosed Snakes prefer areas in Illinois with sandy soil.
Here’s why:
Eastern Hog-nosed Snakes primarily prey on toads and use their upturned snout to dig for them in their burrows. They also have enlarged teeth at the rear of the upper jaw that they use to puncture and deflate toads that puff up when threatened. These snakes also have large adrenal glands, which secrete large amounts of hormones to counteract the toad’s potent skin poison!
When disturbed, Eastern Hog-nosed Snakes lift their head off the ground and flatten their neck like a cobra! They may also hiss and false strike with a closed mouth.
If this display fails to scare off a predator, then the snake will play dead. They’ll roll onto their back, let their tongue hang out, and emit musk from glands near the base of their tail. Interestingly, when the threat has left, the snake will right itself and continue as normal. 🙂
#24. Kirtland’s Snake
- Clonophis kirtlandii
Identifying Characteristics:
- Adults range from 12 to 18 inches in length.
- Coloration is grayish brown, reddish, or dark brown with four rows of alternating, dark, round blotches down the back and sides.
- Bright red, pink, or orange underside.
- Mostly black or dark brown head with white, light-cream, or yellow lips, chin, and throat.
Kirtland’s Snakes are rarely found far from a water source in Illinois. They occupy various wetland habitats, including wet prairies, forested woodlands, floodplains, wet meadows, marshes, and swamps.
These snakes spend a lot of their time in burrows or under objects such as rocks, logs, boards, or leaf litter. During the winter, they hibernate in crayfish or other animal burrows.
Kirtland’s Snakes are reclusive and nocturnal. They feed on small prey, primarily earthworms and slugs. They may also consume crayfish, leeches, small fish, insects, and grubs.
Kirtland’s Snakes are imperiled in all states within their range and are listed as endangered, threatened, or vulnerable. Habitat loss and degradation have played a significant role in the decline of this species. They also face threats from road mortality and the pet trade. Additionally, as these snakes rely heavily on crayfish burrows, any reduction in crayfish populations is detrimental.
#25. Dekay’s Brownsnake
- Storeria dekayi
Identifying Characteristics:
- Adults typically range from 6 to 13 inches in length.
- Coloration is light brown or gray to dark brown or black with two rows of dark spots down the back, which are sometimes linked.
- A dark streak down the head and may have a light stripe down the center of the back.
Dekay’s Brownsnakes occupy various terrestrial habitats as long as there’s plenty of cover available such as rocks, logs, boards, and all sorts of trash and organic debris. They’re often found in backyards and gardens under objects.
These secretive, nocturnal snakes hunt during the evening and night, feeding primarily on slugs and earthworms. However, they’ve also been known to consume snails, insects, insect larvae, small tree frogs, tadpoles, frog eggs, spiders, and fish. Prey is typically grabbed and quickly swallowed alive.
These docile snakes usually don’t bite in defense. Instead, if captured, they often squirm vigorously or flatten their bodies and may release foul-smelling musk from glands near the base of their tail.
This species is considered common in most of its range and is not a major conservation concern. It adapts well to human development and has a reputation as a “city snake.” However, pesticide usage and clean-up of cover objects may reduce their populations in urban areas by reducing their habitat and food source.
#26. Chicago Garter Snake
- Thamnophis sirtalis semifasciatus
Identifying Characteristics:
- Adults reach up to 39 inches in length.
- Coloration is dark brown or black with yellowish stripes down their back and sides.
- The stripes on their sides break into dashed lines near the head.
- The Chicago Garter Snake is a subspecies of the Common Garter Snake.
You’re most likely to find the Chicago Garter Snake in forest and edge habitats. But interestingly, they are only found in the region that surrounds the city of Chicago!
They prefer areas near freshwater sources and can be spotted basking in open areas. These garter snakes are especially cold-tolerant and may even leave hibernation to bask on warm winter days.
Chicago Garter Snakes are similar in behavior and appearance to Eastern Garter Snakes, and both are subspecies of the Common Garter Snake. The main difference is in their appearance. The yellow side stripes on Chicago Garter Snakes are broken into dashed lines near the head.
#27. Eastern Foxsnake
- Pantherophis vulpinus
Identifying Characteristics:
- Adults range from 36 to 72 inches in length.
- Coloration is light golden brown, yellow, or bronze with dark brown or reddish-brown blotches down the back and alternating spots down the side.
- Look for a short, flattened snout.
Eastern Foxsnakes are most often found in Illinois in grasslands, prairies, and farming areas. They much prefer wet areas as opposed to dry and are typically spotted on the ground. But don’t be surprised if you see one of these snakes in a tree, as they are strong, agile climbers.
These snakes are typically diurnal, but they may hunt at night during extremely hot weather. They often hide under rocks, logs, or in burrows to regulate their temperature. During the winter, they hibernate below the frost line in underground burrows.
Foxsnake Range Map
Eastern and Western Foxsnakes are closely related and look the same. In the past, they were even considered the same species before eventually being split apart. The best way to determine the correct species is by location, as they are divided by the Mississippi River.
If disturbed, Eastern Foxsnakes coil and vibrate their tail, producing a rattlesnake-like sound in dry leaves. If grabbed, they will often release a foul-smelling musk which is thought to smell like a Red Fox, giving them their name.
#28. Red-bellied Snake
- Storeria occipitomaculata
Identifying Characteristics:
- A small woodland species that grows between 10 to 25 cm (4-10 in) long.
- Colors vary from orange, gray, black, and brown.
- Their bright red or orange belly stands out from other species.
This species is probably the “cutest” snake in Illinois!
Red-bellied Snakes are small, docile, and have a bright red belly, which makes them VERY easy to identify.
Look for them under logs and leaf litter. They are also commonly found burrowed inside abandoned ant mounds. They are typically diurnal but can be hard to find due to their secretive nature.
Red-belled Snake Range Map
The colors represent the different subspecies of Storeria occipitomaculata.
Red-bellied Snakes have a unique behavior called “lip-curling,” where they curl their lips upward and flick their tongue when eating or feeling threatened. This behavior helps them catch their prey and also scares off potential predators.
Unfortunately, people often kill this species out of fear. This is incredibly sad because these snakes are harmless and valuable to the ecosystem. In addition to this senseless slaughter, many are killed while crossing roads.
#29. North American Racer
- Coluber constrictor
Identifying Characteristics:
- Adults typically range from 50 to 152 cm (20 to 60 in) in total length
- The patterns and texture of their skin vary widely among subspecies. However, most are solid-colored and have a lighter-colored underbelly.
True to their name, North American Racers are one of the FASTEST snakes in Illinois!
When they get moving, they can speed away at up to 3.5 miles per hour (5.6 kph). These active snakes are curious and have excellent vision. In fact, they are known to raise their heads above the height of the grass to view their surroundings.
Despite their scientific name (constrictor), North American Racers do not squeeze their prey to death. Instead, they subdue their victim by holding it down with their body. Smaller prey is simply swallowed alive.
North American Racer Range Map
These nonvenomous snakes fight back incredibly hard if they feel threatened or become trapped. You can expect them to bite, thrash, defecate, and release a foul-smelling musk, especially if you try holding one. In addition, racers will try to impersonate rattlesnakes by shaking their tails in dry leaves.
North American Racers are still abundant in many places. But they face threats as they are losing habitat to urbanization and development. Unfortunately, many people also kill them out of fear, even though they are completely harmless, especially if you leave them alone.
#30. Ring-necked Snake
- Diadophis punctatus
Identifying Characteristics:
- These snakes are usually solid olive, brown, bluish-gray, or smoky colored. Look for a distinctive yellow or red neckband.
- The snake’s head color is usually slightly darker than the rest of the body, tending towards black rather than gray or olive.
- Adults are usually between 25-38 cm (10-15 in) long.
It can be hard to find these snakes in Illinois!
That’s because Ring-necked Snakes are VERY secretive and spend most of their time hiding in areas with lots of cover. In addition, they are nocturnal and rarely seen during the day.
Ring-necked Snake Range Map
The colors represent the different subspecies of Diadophis punctatus.
If you come across one, you may see its unique defense posture. Red-bellied Snakes will curl their tails and expose their bright red-orange bellies when they feel threatened in hopes of scaring you away.
Ring-necked Snakes mostly eat small salamanders, earthworms, and slugs. Not much is known about their population status because they are so hard to find!
#31. Eastern Worm Snake
- Carphophis amoenus
Identifying Characteristics:
- Small snakes that measure 19-28 cm (7.5–11.0 in) in total length.
- Their bodies are brown, and their bellies are pink.
- Females are typically longer than males.
Consider yourself lucky if you ever see an Eastern Worm Snake in Illinois!
These small snakes spend most of the year underground or in rotting logs. They are usually found in forests with lots of leaf litter and canopy cover, which helps them avoid heat and dehydration.
Eastern Worm Snake Range Map
Credit: Virginia Herpetological Society
Eastern Worm Snakes prefer moist soil inhabited by earthworms, which are their main prey. Their skin naturally evaporates water, so the soil needs to be moist enough to offset this. The best chance to spot a worm snake is after heavy rains, which force them out from underground.
Eastern Worm Snakes are completely harmless to humans. The worst thing they can do is release a foul-smelling liquid when they are handled.
Do you need additional help identifying snakes in Illinois?
Try this field guide!
Which of these SNAKES have you seen before in Illinois?
Leave a comment below!
Also, if you enjoy this article, make sure to check out these other Illinois guides!
-
14 FROGS Found in Illinois! (ID Guide)
-
16 Types of TURTLES in Illinois! (Both Aquatic and Land)
-
7 Kinds of LIZARDS That Live in Illinois!
