Common Pests in Indiana: Identification, Prevention & When to Call a Pro

·October 26, 2026·12 min read

Quick Summary

Indiana homes deal with termites, carpenter ants, mice, spiders, stink bugs, cockroaches, bed bugs, and stinging insects.
Most pests get inside through small gaps. A mouse can squeeze through an opening about ¼ inch wide.
Fall is the busiest season for pests that move indoors to spend the winter.
Termite and carpenter ant damage often stays hidden until the repair bill is large.
A professional pest inspection and home sealing service finds entry points and active problems before they grow.

Why Indiana Homes Attract Pests

Indiana has four distinct seasons, and each one brings a different set of pests. Warm, humid summers support ants, wasps, and termite swarms. When temperatures drop in September and October, mice, stink bugs, and lady beetles look for a warm place to spend the winter. Your house is often the closest option.

Older homes face extra risk. Foundations settle, weather stripping wears out, and caulk cracks around windows. Newer homes have gaps too, especially where pipes, wires, and vents pass through exterior walls. Pests do not need much space. They need one opening and a reason to come inside, such as food, water, or warmth.

Quick Reference: Common Indiana Pests

Pest	Peak season	Where you find it	Main concern
Eastern subterranean termites	Spring swarms, active most of the year	Soil, foundation, wood near the ground	Structural damage
Carpenter ants	Spring and summer	Damp or decayed wood	Structural damage
House mice	Fall and winter	Walls, attics, kitchens, garages	Disease, chewed wires, contaminated food
Brown recluse spiders	Year-round indoors	Dry, cluttered areas, mostly southern Indiana	Venomous bite
Brown marmorated stink bugs	Fall	Windows, attics, wall voids	Odor and nuisance
German cockroaches	Year-round	Kitchens and bathrooms	Allergens, contaminated food
Bed bugs	Year-round	Beds and upholstered furniture	Bites, hard to eliminate
Yellowjackets and hornets	Late summer	Eaves, ground nests, wall voids	Stings

Termites

The eastern subterranean termite is the termite species that damages homes in Indiana. These termites live in the soil and build mud tubes up foundation walls to reach wood. They eat wood from the inside out, so a floor joist or sill plate can look normal while the inside is hollow.

Watch for these signs:

Mud tubes about the width of a pencil on foundation walls, piers, or crawl space walls
Swarms of winged insects indoors in spring, often near windows and doors
Piles of discarded wings on windowsills
Wood that sounds hollow or crumbles when you press a screwdriver into it
Paint that bubbles or looks uneven on wood trim

Many homeowners mistake termite swarmers for flying ants. Termite swarmers have straight antennae, a thick waist, and two pairs of wings of equal length. Flying ants have bent antennae, a pinched waist, and front wings that are longer than the back wings.

Carpenter Ants

Carpenter ants are large black ants, often ¼ to ½ inch long. They do not eat wood. They chew tunnels in it to build nests and push out a coarse, sawdust-like material.

Carpenter ants prefer wood that is already damp or soft. Common nest sites include window frames, areas under roof leaks, wood around bathtubs, and porch columns.

Signs of a carpenter ant problem:

Small piles of coarse sawdust under baseboards, windows, or door frames
Large black ants indoors, especially at night
A faint rustling sound inside walls
Winged ants indoors in spring

A carpenter ant colony usually points to a moisture problem. Treating the ants without fixing the leak gives a new colony the same opportunity. If you see ants near the ceiling or attic, check the roof.

House Mice and Rats

Mice are the most common cold-weather pest in Indiana homes. They move indoors in fall and stay through winter. A mouse can squeeze through a gap about ¼ inch wide, which is roughly the width of a pencil.

The CDC lists the places to check for rodent entry points, including the gap between the foundation and the ground, attic and crawl space vents, and holes around electrical, plumbing, cable, and gas lines. Garage doors and dryer vents are other common entry spots.

Signs of mice:

Droppings about the size of a grain of rice in cabinets, drawers, or along walls
Gnaw marks on food packaging, wood, or wiring
Shredded paper, insulation, or fabric in hidden corners
Scratching sounds in walls or ceilings at night
Dark grease marks along baseboards where mice travel

Rodents carry diseases and contaminate food. Mice also chew on electrical wires, which creates a fire risk. When you clean up droppings, wear gloves and use a disinfectant spray. Do not sweep or vacuum dry droppings, since this puts particles in the air.

Spiders

Indiana has around 400 spider species, and the Indiana Department of Natural Resources notes that only two can cause serious injury to people: the brown recluse and the black widow. Neither one is aggressive, and bites are rare.

Brown recluse: This spider is tan to dark brown with a violin-shaped mark on its back. With legs stretched out, it is about the size of a half dollar. It has six eyes instead of eight. Indiana State University's research team reports that the brown recluse lives in almost any county in the southern half of Indiana and becomes less common farther north. It prefers dry, undisturbed spots such as closets, storage boxes, basements, and garages.

Black widow: This spider is shiny black with a red hourglass shape on its underside. It rarely lives inside homes. Look for it in woodpiles, sheds, and under outdoor furniture.

Purdue Extension's spider fact sheet covers identification in more detail. Most spiders in your home are harmless and eat other insects. A large number of spiders often means your home has plenty of other insects for them to eat, which is a sign of entry gaps worth sealing.

Fall Invaders: Stink Bugs, Lady Beetles, and Boxelder Bugs

The brown marmorated stink bug is an invasive insect from Asia. It first appeared in Indiana around 2010 and is now a familiar fall nuisance across the state. Asian lady beetles and boxelder bugs follow the same habit.

These insects gather on sunny exterior walls in late summer and early fall. They then crawl into wall voids, attics, and window frames to spend the winter. On warm winter days, they wake up and wander into living spaces.

They do not bite people or damage the structure. Stink bugs release a strong odor when you crush them, and lady beetles can stain surfaces. Purdue's guide to brown marmorated stink bugs in homes suggests a vacuum or a broom and dustpan for the ones that get inside. Sealing gaps before September is the best way to keep them out.

Cockroaches

The German cockroach is the most common indoor cockroach. It is light brown with two dark stripes behind the head and is about ½ inch long. German cockroaches usually arrive in grocery bags, cardboard boxes, or used appliances. They hide near heat and moisture, such as behind refrigerators, under sinks, and inside dishwasher panels.

They breed fast, and one female can produce hundreds of offspring in a year. Store-bought sprays often push them deeper into walls. Professional baiting programs and crack-and-crevice treatments work better for an established population.

Bed Bugs

Bed bugs travel in luggage, backpacks, and secondhand furniture. They hide in mattress seams, box springs, headboards, and the edges of carpet.

Signs of bed bugs:

Small rust-colored spots on sheets or mattress seams
Tiny pale eggs and shed skins in cracks near the bed
Itchy bites in a line or cluster, often on arms and shoulders

Bed bugs are hard to eliminate on your own. The EPA offers guidance on finding and controlling bed bugs, but most infestations need professional heat treatment or a targeted treatment plan with follow-up visits.

Wasps, Yellowjackets, and Hornets

Stinging insect colonies reach their largest size in late summer. Yellowjackets often nest in the ground or inside wall voids. Bald-faced hornets build large paper nests in trees and under eaves. Paper wasps build open, umbrella-shaped nests under porch roofs and railings.

A nest inside a wall needs a professional. If you seal the entry hole, the trapped wasps can chew through drywall and come into the house. People with allergies to stings should never try to remove a nest themselves.

Seasonal Pest Calendar for Indiana

Season	What to watch for	What to do
Spring (March to May)	Termite swarms, carpenter ants	Check the foundation for mud tubes and fix roof or plumbing leaks
Summer (June to August)	Ants, wasps, yellowjackets, cockroaches	Trim shrubs away from siding and check eaves for nests
Fall (September to November)	Mice, stink bugs, lady beetles, spiders	Seal gaps and replace worn weather stripping before temperatures drop
Winter (December to February)	Mice, cockroaches, overwintering insects	Check the attic, basement, and garage for droppings and nests

Signs You Need a Professional Pest Inspection

Call a pest control professional if you notice any of the following:

Mud tubes on your foundation or in the crawl space
Winged insects swarming indoors
Droppings in more than one room
Sawdust piles near wood trim or framing
Bites you cannot explain, or blood spots on sheets
Insects that keep coming back after you treat them
A wasp or yellowjacket nest inside a wall
You are buying or selling a home

What You Can Do Yourself

You can lower the chance of a pest problem with some basic maintenance:

Seal small gaps. The CDC recommends filling small holes with steel wool and holding it in place with caulk.
Cut back vegetation. Keep shrubs, tree branches, and vines a few feet away from your siding and roof.
Move wood and mulch. Store firewood away from the house and keep mulch beds thin near the foundation.
Control moisture. Fix leaky faucets and pipes, clean gutters, and run a dehumidifier in damp basements.
Store food tightly. Use sealed containers for pantry food and pet food.
Check door sweeps. If you can see daylight under an exterior door, mice can get in.

Our room-by-room home maintenance checklist includes these tasks along with other seasonal jobs.

DIY steps help, but they have limits. Many entry points sit in places that are hard to see, such as the sill plate, the roofline, or behind siding. Termites and carpenter ants also need a trained eye and professional treatment.

What a Pest Inspection and Home Sealing Service Includes

A professional pest inspection covers the inside and outside of your home. The technician checks the foundation, crawl space, basement, attic, garage, and roofline. They identify active pests, look for damage, and point out conditions that attract pests, such as moisture or wood-to-soil contact. You should receive a written report and a treatment plan. Our guide to pest inspections and what they include explains the process step by step.

A home sealing service, also called exclusion, closes the gaps that let pests in. A typical sealing job includes:

Sealing gaps around pipes, wires, and utility lines
Installing door sweeps and replacing worn weather stripping
Covering attic, soffit, and crawl space vents with sturdy mesh
Filling gaps along the foundation and roofline
Capping chimneys and sealing gaps around dryer and exhaust vents

	DIY sealing	Professional sealing
Materials	Caulk, steel wool, foam	Copper mesh, hardware cloth, metal flashing, rodent-proof sealants
Areas covered	Easy-to-reach gaps	Roofline, sill plate, crawl space, attic
Pest identification	Limited	Full inspection and written report
Follow-up	None	Monitoring and warranty options

How to Choose a Pest Control Company in Indiana

Indiana requires commercial pest control firms to operate under the state's pesticide use and applicator law. You can check a company's credentials through the Office of Indiana State Chemist.

Before you hire, ask these questions:

Is the company licensed in Indiana, and are the technicians certified?
Does the company carry liability insurance?
Will I get a written inspection report and treatment plan?
What warranty comes with termite treatment or sealing work?
How many follow-up visits does the price include?

If you want to understand the difference between a license, a bond, and insurance, read Licensed, Bonded, and Insured: What These Three Words Actually Mean.

Get Matched With a Trusted Pest Control Pro

You do not have to search through dozens of listings to find a reliable pest control company. My Licensed Contractor screens contractors and matches homeowners with qualified local pros. Tell us what you are seeing, whether that is mice in the attic, mud tubes on the foundation, or stink bugs at every window. We connect you with a pest control professional who can inspect your home and seal the gaps that let pests in.

Submit your pest inspection or home sealing request on My Licensed Contractor and get matched with a pest control pro in your area.

Frequently Asked Questions

What is the most common pest in Indiana homes?

House mice are the most common pest inside Indiana homes during fall and winter. In warmer months, ants and stinging insects cause the most calls. Termites are less visible but cause the most structural damage.

Are there termites in Indiana?

Yes. The eastern subterranean termite lives throughout Indiana. It nests in the soil and reaches wood through mud tubes, so damage can go unnoticed for years.

When should I seal my home against pests in Indiana?

Late summer and early fall is the best time. Sealing in August or September keeps out mice, stink bugs, and lady beetles before they move indoors for winter.

Are brown recluse spiders common in northern Indiana?

Brown recluse spiders live mostly in the southern half of the state and become less common as you travel north. Black widows live statewide but rarely come indoors.

How much does a pest inspection cost?

Prices vary by home size and the type of inspection. A general pest inspection usually costs less than a full termite inspection for a real estate sale. Ask for the price in writing before the visit, and ask whether the fee goes toward treatment if you hire the company.

Can I get rid of pests without a professional?

You can handle a few stray insects and seal small gaps yourself. Termites, carpenter ants, bed bugs, cockroach infestations, and wasp nests in walls need a professional. Treatment that misses the source usually leads to the pests coming back.