Spiders and snakes are everywhere in Indiana. Here’s how to identify them.

Spending the summer outdoors means running into a variety of crawling and slithering creatures, whether it's at the lake, on the forest floor or wrapped around your front porch light. While running into these critters can be scary, they are largely harmless. 

Whether you’re petrified of the creepy crawlies or curious, here’s everything you need to know about encountering spiders and snakes in southern Indiana.

What spiders and snakes am I likely to see in Indiana?

Spider sightings vary depending on where you are, said Dr. Marc Milne, a University of Indianapolis professor who runs a spider research lab. 

At home, you may encounter spiders that love human dwellings, like cellar spiders, also known as daddy long legs, spindly creatures that eat insects and other spiders in the home, or comb-footed spiders, which build haphazard webs in a home's nooks and crannies and eat ants. 

Outdoors, people are likely to find larger, hunting spiders including wolf spiders, ground spiders and nursery web spiders. In orchards or forests, you may encounter a waist-high, horizontal web, likely the work of delicate, leaf-green orchard spiders. 

Common snakes in Indiana include garter snakes, milk snakes, ribbon snakes, rat snakes and a variety of non-venomous water snakes. 

Which spiders in Indiana are venomous?

There are over 400 species of spiders in Indiana, though only two are dangerous to humans, according to the Indiana Department of Natural Resources. These are the brown recluse spider and the southern black widow spider. 

The venom from these spiders can cause severe pain, trouble breathing, dizziness and nausea in some people, in which case medical intervention is necessary. However, reactions vary depending on age, allergies and immune system strength, and fatalities are rare. Milder symptoms of a brown recluse bite may include itching and reddened, blistered skin.

About a week after the bite, an open sore develops along with a breakdown of tissue due to the spider’s necrotic venom. Unlike the brown recluse, the black widow’s venom is a neurotoxin, meaning it affects the nervous system with symptoms ranging from muscle cramps and weakness, fever, vomiting and increased heart rate and blood pressure.

Neither spider is aggressive, usually only biting when they feel threatened. In his 20 years of working with spiders, Milne said he has never been bitten. He said spiders’ first defense is always to run away from humans; biting is typically a last-ditch effort when the creatures feel they have nowhere to run. 

Milne said brown recluse bites are often misdiagnosed, as they appear similar to wound infections with necrotic bacteria. If the person didn’t see the spider bite them, it’s most likely bacteria, he said.

When someone is bitten, Milne recommends capturing the spider so an expert can identify it. 

Which venomous snakes are found in Indiana?

Indiana has 32 native snake species of which four are venomous, according to the Indiana Department of Natural Resources — copperhead snakes in the southern half of the state, cottonmouth snakes in southwestern Indiana, the eastern Massasauga rattlesnake in the northern third of Indiana and the timber rattlesnake in south-central Indiana. Cottonmouths and timber rattlesnakes are endangered in the state while the eastern Massasauga rattlesnake is federally threatened. 

The DNR recommends leaving snakes alone, as they usually bite out of self-defense.

These rare snake bites can cause numbness, nausea, severe pain and swelling. Those who are bitten by a venomous snake should contact 911 immediately while remaining calm and keeping the bite at heart-level. 

How can I identify spiders and snakes in Indiana?

If you’re curious the next time a spider darts through your crawlspace or spins a gorgeous, dew-covered web, there are several easy ways to identify the species. 

Milne recommends the Facebook group “All Bugs Go To Kevin,” run by Milne’s friend and self-described arthropod educator Kevin Wiener. The group, which has more than 181,000 members, offers a place for people to post photos of spiders and other bugs to identify and learn more about the creatures they encounter.

Alternatively, there are several apps that allow you to snap a photo of a spider or snake to identify them. Seek, a free app by iNaturalist, can be used to identify all types of arachnids, plants, fungi, insects and other animals. It also has a map that shows where users of the app have found a certain species near you. 

Another app, Picture Insect: Spiders and Bugs, offers a similar function in addition to a chatbot that can help people identify bug bites. When you download the app, it prompts you to purchase a premium subscription, although this screen can be dismissed to access the free version of the app.

What if I've been bitten by a spider or snake?

Though bites from venomous snakes are dangerous without medical attention, fatalities are rare. Each year between 7,000 and 8,000 people in the U.S. are bit by venomous snakes, the Center for Disease Control and Prevention estimates, and approximately five of those people die.

To avoid a snake bite, maneuver carefully around logs and rock piles where snakes are likely to hide and listen for the rattle of a camouflaged rattlesnake. 

Ultimately, snakes serve an important role as they provide food for larger animals and keep pest populations like slugs and rodents under control.  

Spiders are also a critical part of the ecosystem, Milne said. Spiders don’t carry diseases that can infect humans and eat pests that do, reducing the pest population for the good of human and crop health. 

Brown County resident Bailey Russell said she thinks the fear of spiders and snakes is taught, not innate. When she shows spiders and snakes as an intern for the Brown County Soil and Water Conservation District, she said it’s always the little kids who are eager to get closer to the creatures. 

Whenever non-house spiders accidentally make their way inside, Russell recommends gently returning them to the outdoors with a piece of paper and a cup, or offering a wet Q-Tip as a drink to the thirsty critter. The act can help show people that spiders are just trying to survive like any other animal, she said. 

When it comes to unwanted snakes spotted around a home, Russell said people can encourage a snake to move along by gently spraying it with a hose. A more permanent solution is snake relocation — Russell suggested the Facebook group “Free Snake Relocation Directory” to find resources. 

However, snakes generally prefer to hide, Russell said, so they will probably move along on their own and do their best to stay out of sight.

“Snakes are nature — they’re part of it. We can't have it without them,” she said. “So I think acceptance is probably the best move.”

Reach Marissa Meador at MMeador@gannett.com.