Copperheads in Illinois: Where They Live and How Often They Bite

Written by Emmanuel Kingsley
Published: June 26, 2022
© Joe McDonald/
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Copperheads are a very popular snake species in North America. In the U.S particularly, these snakes are notorious biters. Copperheads are one of the four venomous snakes found in Illinois. The state’s deciduous forest and mixed woodlands are particular favorites for copperheads.

Like many snakes, their birthing season spans from mid-August to early October. If you live in Illinois and would like to safely observe or totally avoid Illinois’s copperheads, this article has got you covered. Discover where copperheads in Illinois live and how often they bite.

What Copperhead Species is Found in Illinois?

Eastern Copperhead
The eastern copperhead is the only copperhead species in Illinois.

©Jeff W. Jarrett/

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Illinois is home to only one copperhead species; the eastern copperhead. The eastern copperhead is a North American pit viper from the Crotalinae subfamily and the Viperidae family. The species is vastly distributed across the many states in the US.

Eastern Copperheads

Eastern copperheads, like all pit vipers, have infrared pit organs that allow them to detect the presence and movements of their prey through their body heat. They are stalk and ambush hunters who lie in wait for their prey for as long as they need to.

They also have solenoglyphous fangs, which are the longest fang type. Solenoglyphous fangs work like hypodermic needles, breaking the skin and injecting venom from the gland into the victim. Like many snakes, they are diurnal in the spring and fall and nocturnal during the summer.

How To Identify Eastern Copperheads

Eastern copperheads are thick-bodied and measure 20 to 37 inches on average. Weight-wise, they vary between 3.2 and 11.2 ounces (0.2 – 0.7 pounds).

As their name implies, these snakes have triangular orange-red or copper heads. Their dorsal and ventral scales are colored pale brown to pinkish-brown and patterned by hourglass-shaped markings colored copper to reddish-brown.

Where Are Copperheads Found in Illinois?

The Copperhead’s scales are keeled, and their eyes have vertical pupils that make them resemble cat’s eyes.
The Copperhead’s scales are keeled, and their eyes have vertical pupils that make them resemble cat’s eyes.

©Creeping Things/

According to the Illinois Division of Research Safety, the southern one-third of the state, along the lower Illinois River valley, and south of Route 16 are vastly populated with copperheads. This is because these areas are awash with sandstone outcroppings, deciduous forests, river bluffs, mixed woodlands, and upland forests.

How Often Do Copperheads in Illinois Bite?

The body of the Copperhead ranges from 2 to usually less than 4 feet, but it is robust.
About 7,000 to 8,000 people are bitten by snakes each year in the US, and copperheads are responsible for 2,920 of these incidents.


Illinois sees the most copperhead activity and bites from May to October. About 7,000 to 8,000 people are bitten by snakes each year in the US, and copperheads are responsible for 2,920 (roughly 38.9%) of these incidents. This is because they act differently from other snakes who run away once they sense human activity.

Instead, copperheads freeze and blend into their surroundings. This often causes humans not to notice them and consequently step on or near them. These snakes then react defensively by biting to protect themselves from the perceived attack from the unsuspecting human.

Copperhead Venom

Copperheads have primarily hemotoxic venom, which attacks the circulatory system and causes respiratory issues. Hemotoxins also attack the muscle tissue, which can result in hemorrhaging. In more severe cases, they can cause the death of cells in the affected areas and hinder or cause blood clotting.

Their bites are also very painful and result in severe nausea and swelling. However, their venom isn’t very toxic. The eastern copperhead’s maximum venom yield is 85mg, but they emit only 26mg on average, and their bites are often dry or venom-free. Also, it takes at least 85-100mg to kill a human (lethal venom dose/ LD50). Considering the figures, it’s understandable why only a few cases lead to deaths. Only 0.01% of their bites are fatal. Despite this figure, it is important to realize that their bites still kill people.

How To Avoid Copperhead Bites in Illinois

Copperheads hide or camouflage under rocks, piles of leaves, debris, or logs, so if you’re going for a walk, be sure to avoid these places. Another way to avoid copperheads is by sticking to defined paths. Like most snakes, copperheads go out of their ways to avoid humans and will mostly steer clear of popular paths.

If you’re trying to keep copperheads off your property, you can do this by keeping your surroundings clean and planting snake-repelling plants.

What To Do If You Come Across A Copperhead in Illinois

If you come across a copperhead in Illinois, respect its boundaries and leave it alone. Most snake bites occur due to humans who aggravate snakes intentionally or mistakenly.

However, if you spot a copperhead in your home, exit as soon as possible and be sure to take your pets too, if you have any. Once you’re a safe distance away, contact a pest control center for help.

What To Do If You Get Bitten By A Copperhead Snake

If you get bitten by a copperhead (or any snake, for that matter), contact emergency services immediately. You can contact the Illinois Poison Center at 800-222-1222. Your ability to recognize the bite will let the doctors know the exact antivenom you need. However, doctors are smart enough to figure it out even if you cannot identify the snake- so don’t panic.

While waiting for emergency medical services, sit still and resist the urge to pace around. This is because any sort of motion will aid the venom in circulating. Do not attempt to treat yourself. This includes sucking the venom out, tying a tourniquet, or worse, attempting to cut off the bitten part. Sucking the venom out will not get all of it out. Instead, you’ll have snake venom in your body and mouth.

Similarly, cutting off the bitten part is another terrible step you can take. For one, it is unnecessary as you’ll be losing a body part when you can simply get a shot of antivenom. Secondly, you could now bleed to death, and if the venom has already spread, you’ll be decreasing your chance of survival by the minute.

Many people have survived snake bites. Stick to these tips, and you’ll be fine.

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