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According to the Illinois Department of Natural Resources, there are four venomous snakes native to Illinois. They are mainly found in southern Illinois, but can be potentially anywhere in the state. They favor woodpiles and sheds.

All four are a part of the snake family called Crotalinae:

  • The copperhead –can be found in the southern part of Illinois, south of Route 16. This is the least harmful of the four.
  • The cottonmouth (also known as the water moccasin) – live in swamps and wet bottomlands in southern Illinois, south of Route 13.
  • The timber rattlesnake – can be found in the southern part of the state (south of Interstate 64), mostly in the Illinois River Valley and the Mississippi River Valley.
  • The eastern massasauga – can be found scattered within the counties of Madison, Clinton, Piatt, Knox, Warren, Will, Cook, and Lake.

The #1 first aid device to have when bit by a snake is a cell phone to call for help. Poor choices for first aid include suction devices, cutting the wound with a pocket knife, and tourniquets. These cause harm.


There are over 6,000 snake bites reported to the nation’s poison centers annually, and we tend to see many of them in the warmer months.

Over 67% of bites in one study occurred because the person was intentionally handling the snake (usually a pet) and 22% had been bitten previously. If you have a venomous snake that doesn't enjoy being handled, a serious bite could result. Studies report between 60%-70% of bites occur on an upper extremity, usually the finger or hand. Someone who inadvertently steps on a snake in the wild would be expected to be bit on the legs or feet. Alcohol is involved in 50-65% of snake bites where the person is intentionally handling the snake.

If bitten by a snake, the patient should:

  • Immobilize the affected limb.
  • Remove any jewelry such as rings, bracelets and watches.
  • Be transported to the nearest emergency department immediately.
Do not apply ice or heat, tight tourniquet, electric shocks, conduct oral suctioning, or make incisions to the bite area for crotaline snakes.



  • When you encounter a snake, back off! Venomous snakes are not aggressive and tend to bite people only when stepped on, picked up or cornered.
  • Choose your pets wisely. Avoid dangerous animals, such as poisonous snakes or pythons. Some daring people keep pythons (boa constrictor) as house pets. Pythons are non-venomous, however can inflict painful bite injuries .
  • Take proper precautions when hiking or camping in areas where snakes reside.
  • Wear leather boots.
  • Do not reach under rocks or logs.
  • Do not step over rocks or logs, and look around before you sit.
  • Do not attempt to handle, touch, move, or feed a wild snake.
  • Do not purchase poisonous snakes as pets. An astounding amount of snake bites reported in Illinois were courtesy of non-native species to Illinois.
  • Do not attempt to overpower, handle or trap dangerous and poisonous reptiles.
  • Do not handle a (presumably) dead venomous snake, as they may still deliver a dangerous bite.