Most Missouri snakes are good at pest control. Some are venomous. Ideally it's best to let them be.

Sara Karnes
Springfield News-Leader

There are dozens of slithery reptiles in Missouri, and with the summer heat, there's a chance you'll see more snakes. 

Of the nearly 50 species and subspecies of snakes in Missouri, six are venomous, and all play an important role in our ecosystem, said Francis Skalicky, media specialist for Missouri Department of Conservation.

The reptiles eat rodents, such as mice and rats, small animals and some insects in the wild.

"Snakes can be very good pest control," Skalicky said. "A lot of people grew up thinking, 'The only good snake is a dead snake,' and that's not the case at all."

'Seeing a snake in the wild is nothing you need to be scared of'

The Wildlife Code of Missouri treats snakes, lizards and most turtles as nongame. This means that there is no open season on these animals, and it is technically unlawful to kill them.

"There's a comfort level and there's a safety level that you also need to think about, but just remember that these snakes are doing a benefit," Skalicky said. "Seeing a snake in the wild is nothing you need to be scared of and nothing that you need to kill."

There are concessions, such as if a venomous snake is in close enough vicinity of someone or property that they could harm. Snakes inside buildings are situationally specific and may require different ways to handle, Skalicky said.

Occasionally, people will misjudge the pattern on a prairie kingsnake for a copperhead and kill it.

"The irony of that particular situation is a prairie kingsnake is immune to venom and one of the things that actually kills our copperheads," Skalicky said. "When you kill a prairie kingsnake, you haven't decreased your chance of seeing a copperhead. You've actually increased your chance because you've taken out one of its predators."

The who's who of venomous snakes in Missouri

The six venomous snakes native to Missouri are members of the pit viper family, and they include: eastern copperhead, northern cottonmouth, timber rattlesnake, eastern massasauga, prairie massasauga and western pygmy rattlesnake.

Eastern copperheads are the state's most common venomous snake and can be found on rocky hillsides and along the edges of forests. They also spend time among trees and in brush along prairie streams. Copperheads, often found near abandoned farm buildings, will vibrate their tails when alarmed.

Northern cottonmouth are known as water moccasin. These reptiles are semi-aquatic and got their name because of the cotton-white lining of its mouth. They live in two different habitats: in southeastern Missouri, they live in swamps and oxbow lakes, while in the southern Ozarks, they live in rocky streams and rivers.

The cottonmouth is a dangerously venomous species that can deliver a fatal bite.

"Various harmless snakes, especially water snakes, are often misidentified as cottonmouths," according to MDC's field guide on snakes.

Timber rattlesnakes is Missouri's largest venomous snake. They live on rocky, wooded hillsides. Using camouflage, timber rattlesnakes will hide to avoid being seen, but will bite if harassed. It is dangerously venomous and medical attention must be immediately sought if bitten.

Known as the swamp rattler, eastern massasauga live in marshy areas or wet prairies. They are found along the Mississippi River floodplain from the St. Louis area to northeastern Missouri. 

A cottonmouth gapes its mouth in a defensive posture, showing the white lining that is the origin of the common name.

"However, this rattlesnake is state-endangered and has not been seen in the state for many years," according to MDC.

Prairie massasaugas live in bottomland or wet prairies. Human deaths caused by its bite are rare, but studies show that the massasauga’s venom is highly toxic, so it must be respected.

"This snake has declined drastically due to the draining of wetlands and conversion of prairies for agriculture and pastureland," MDC says. 

Western pygmy rattlesnake is known as the ground rattler and is one of the smallest species of rattlesnakes in North America. They live under rocks on glades and woodlands while being "so secretive that few people encounter it," according to MDC. The vibrating rattle sounds like a faint buzz of a grasshopper.

While the bite of a western pygmy rattlesnake is not fatal, they should be left alone.

Poisonous v. venomous

Some people may use the wrong words to describe snakes, one being that snakes are poisonous, but they are, in fact, venomous.

"If you eat it and it gives you a toxic reaction, that is poisonous, but if it delivers a venom, that's venomous, so like a spider and a plant," Skalicky said.

The head of a venomous snake is much more defined than a non-venomous. Another difference is that venomous snakes have elliptical pupils while non-venomous have round pupils.

"If you can tell this difference, perhaps you're too close to the snake," Skalicky said, joking.

"A Guide to Missouri's Snakes" can be found online at: https://mdc.mo.gov/sites/default/files/mo_nature/downloads/page/MissouriSnakes.pdf

Sara Karnes is an Outdoors Reporter with the Springfield News-Leader. Follow along with her adventures on Twitter and Instagram @Sara_Karnes. Got a story to tell? Email her at skarnes@springfi.gannett.com.