Venomous Snakes
copperhead ( Agkistrodon contortrix ) cottonmouth ( Agkistrodon piscivorus )
timber rattlesnake ( Crotalus horridus ) eastern massasauga ( Sistrurus catenatus )
Is it poisonous or venomous? Learn to identify, and avoid these Found in heavily timbered areas There is a difference. snakes when possible. with river bluffs and rock outcrops in Copperheads have a light tan or the southern one-fourth of the state, poisonous plant or animal rusty ground color and 10-20 darker the lower Illinois and Mississippi river causes harm if touched or brown, hourglass-shaped crossbands valleys and a few other locations is the consumed. Venomous that are narrow on the back and widen timber rattlesnake . These stout-bod - organisms inject a toxin to on the sides. Locally abundant in wood - ied snakes are gray to light yellow to subdue their prey, as is ed, rocky hillsides in the southern one- greenish-white, with 20-25 black, dAone by the hollow fangs of the four third of Illinois, south of Route 16, and jagged bands, and sometimes a rusty species of pit vipers found in Illinois— in the lower Illinois River valley, cop - stripe down the back. A dark stripe is copperhead ( Agkistrodon contortrix ), perheads prefer upland forests or bluffs behind each eye. Timber rattlesnakes cottonmouth ( Agkistrodon piscivorus ), with limestone or sandstone outcrop - are listed as threatened in Illinois. timber rattlesnake ( Crotalus horridus ) pings. Prairie wetlands, wet oldfields and and eastern massasauga ( Sistrurus cate - The stout-bodied cottonmouth is river floodplains in Madison, Clinton, natus ). The pit is a large opening relatively abundant in swamps, sloughs Piatt, Knox, Warren, Will, Cook and between the eye and nostril used to and wet bottomlands in extreme south - Lake counties provide habitat for the detect heat emitted by their prey. Ven - ern Illinois, south of Illinois Route 13. state-endangered Eastern massas - omous snakes in Illinois also have an Young snakes have 12-18 dark cross - auga . The smallest venomous snake in elliptical pupil. bands on a brown or dark-brown back, Illinois, massasaugas are light brown to Venomous snakes are not aggressive and a wide, dark stripe from the nose gray and have 29-40 light-edged brown and tend to bite people only when through the eye and upper lip. Older or black spots down their back and stepped on, picked up or cornered. adults are dark olive or black. When three rows of smaller blotches along threatened, cottonmouths open their each side. A small rattle is at the end of 20 / Outdoor Illinois March 2010 mouth, displaying a whitish lining. the tail.