Common House Bugs in Ohio

This guide covers the bugs Columbus homeowners and renters ask about most, using Ohio State University Extension fact sheets wherever one exists. For each one I cover what it is and whether it does harm, then what helps and when to call someone. If you cannot match what you found to anything below, a photo is the quickest answer.

Fall invaders

These three move in from September into November, looking for a protected place to spend the winter. They do not damage the house, and spraying inside does little. The fix is sealing gaps before they arrive. In Columbus, the median first fall freeze at John Glenn airport is October 29, from our NOAA record for 2001 to 2025, and the invaders are usually already moving in by then.

Nights at 32°F or colder by month (when mice move indoors)

Brown marmorated stink bug

A shield-shaped bug about 5/8 inch long. It is mottled brown and gray. Its antennae have light and dark bands near the tips. OSU says it was first documented in Ohio in December 2007, in Franklin County. Adults start flying to winter shelter in early September, with a peak in late September or early October, and they get in around windows and chimneys and through window air conditioners.

They do not bite people or pets. When disturbed they give off a "pungent acrid odor." OSU's advice: caulk gaps around window and door trim and around exhaust fans; repair torn screens; take window air conditioners out for winter; vacuum up the ones that get in and throw the vacuum bag away promptly. The fact sheet says plainly: "Insecticides should not be used inside houses after the insects have gained access."

Multicolored Asian lady beetle

A domed beetle about 1/4 inch long. Its color varies widely; the reliable mark is a black "M" or "W" on the white area behind the head. OSU says in Ohio they start looking for winter sites around mid to late October, after the first day above 64F that follows a sharp cold snap, and they gather on the sunny side of a house.

Bites are rare and cannot break the skin. The bigger problem is the yellow-orange fluid they release when disturbed, which smells bad and can permanently stain walls and carpet. OSU also notes that some people are allergic to it; the reactions it lists include asthma and hives. Seal gaps of about 1/8 inch around windows and siding, add door sweeps, and remove the beetles with a shop vac or a vacuum with a nylon stocking over the wand so they are not crushed. OSU says not to use foggers.

Boxelder bug

About 1/2 inch long, dark brownish black with red lines on the back, and bright red under the wings. Boxelder bugs look for winter shelter on warm autumn days and get in through cracks around doors and windows and at the roof soffits. OSU says they do not damage the house or its contents and do not harm people, though they can leave fecal spots on curtains and smell when crushed. Caulk the openings and use screens of 16-mesh or finer. Vacuum up or pick up the ones that get inside. OSU calls indoor insecticide control "impractical and difficult" since the bugs end up scattered through the house.

For all three, the one paid service I would consider is an exterior treatment in late summer, before they move in. OSU's lady beetle fact sheet says exterior residual treatments in late September or early October may help.

Basement and bathroom bugs

These four all follow moisture. In a Columbus house built before 1960, which describes 35% of homes in the city's ZIPs (Census ACS, in our Columbus pest data), if the basement is damp, a dehumidifier often does more than any spray.

House centipede

The fast, gray-yellow centipede with long banded legs, about 1 to 2 inches in body length with 15 pairs of legs. OSU says it is the only centipede that lives in buildings year-round, often in basements and bathrooms, and it eats spiders and cockroaches. Bites are very infrequent. OSU recommends ventilating the basement, running a dehumidifier, sealing foundation cracks and around low windows, and clearing leaf litter in a strip about three feet wide around the house. It says indoor spot treatments are generally not recommended and bug bombs are ineffective.

Silverfish

A flat silvery insect with no wings, 1/3 to 3/4 inch long, with long antennae and three tail-like bristles. OSU says they live in damp, cool places like basements and bathrooms and prefer 75 to 95 percent relative humidity. They are harmless to people but eat paper and book bindings, along with wallpaper paste and the starch in clothing. Lower the humidity, fix plumbing leaks, and get rid of old stacks of newspapers and magazines. Sticky traps help with small numbers. OSU suggests a licensed pest control operator if the problem persists.

Camel crickets

Humpbacked, wingless crickets with very long legs. NC State Extension's fact sheet (revised 2023) says they live outside in moist spots such as under stones and in firewood piles, and come indoors into basements and garages and damp laundry rooms. They are mainly a nuisance, though heavy infestations leave dark fecal smears and can damage stored clothes and linens in boxes. Problems tend to rise after weather extremes like heavy rain or long hot, dry spells. Lower the humidity, keep mulch at least 12 inches from the foundation, weather-strip the doors, and put sticky boards in corners. NC State says pesticides are "not a long-term solution."

Millipedes

Slow, dark, cylindrical, 1/2 to 1 1/4 inches, curling into a "C" when touched. OSU says mass invasions usually happen in late summer and fall, after heavy rain or drought, and that many die indoors from drying out. They do not bite or damage anything. Crushed ones can stain rugs. Clear leaf litter and mulch in a strip about three feet wide around the foundation and seal the cracks. Sweep or vacuum up the ones inside. OSU says indoor sprays and bug bombs are "not effective in preventing millipedes from entering a home."

Clover mites and pantry moths

Clover mites

Tiny reddish-brown specks, about 1/30 inch, crawling on sunny window sills. OSU says they invade from mid-October through December and again from mid-April through mid-June. They do not bite or carry disease. Crushing them leaves a stain, so vacuum them up instead of wiping. OSU suggests a bare strip of soil 18 to 24 inches wide around the foundation, especially on the sunny sides, plus caulking cracks, to help keep them out.

Pantry moths

Small moths in the kitchen are often Indianmeal moths. A 2006 OSU Buckeye Yard and Garden onLine note says they lay eggs in milled grain and seed products, and that the most commonly infested foods are bird seed and dog biscuits. The caterpillars wander away from the food to spin cocoons, so look beyond the bag itself. Throw out infested food outside, freeze anything suspect, and wash the shelves with soapy water. OSU says no chemical is necessary.

Quick reference

Bug	Harm	What helps	Call a pro?
Stink bug	Odor; no bites	Seal gaps in August; vacuum	Only for an exterior treatment
Asian lady beetle	Stains, odor, allergies	Seal gaps; shop vac	Only for an exterior treatment
Boxelder bug	Fecal spots; no damage	Caulk; fine screens	Rarely
House centipede	Rare bite	Dehumidify; seal	If numbers stay high
Silverfish	Paper and fabric damage	Dehumidify; declutter	If it persists
Camel cricket	Fecal smears	Dehumidify; sticky boards	Rarely
Millipede	Stains if crushed	Clear leaf litter	Rarely
Clover mite	Stains if crushed	Bare strip; vacuum	Rarely
Pantry moth	Spoiled food	Toss, freeze, clean	No
Bed bugs, German roaches, termites, carpenter ants	Real	See below	Yes

For the fall invaders and basement bugs, the money is better spent on caulk and a dehumidifier than on a spray plan. If you still want help, ask for an inspection and a written price.

The ones that need a professional

Bed bugs

OSU's 2025 bed bug fact sheet says they have developed resistance to many common insecticide classes and that their small size and fast reproduction make them hard to eliminate. It recommends a company licensed by the Ohio Department of Agriculture. Columbus logged 2,201 bed bug item pickups through 311 in 2024 and 2025. See bed bug treatment and our move-in bed bug guide. The month-by-month 311 numbers are in our data page.

German cockroaches

Small tan roaches in the kitchen. The University of Kentucky's cockroach fact sheet says a single mated female can produce thousands of roaches in less than a year. They need a baiting program with follow-ups. See cockroach treatment.

Termites

OSU entomologists wrote in 2024 that eastern subterranean termites swarm in spring and early summer in Ohio, that Ohio's infestation risk is rated "moderate to heavy," and that control "requires certified professionals." Winged insects in the basement in April are worth a photo. See termite swarm season and termite inspection.

Carpenter ants

Large black ants with coarse sawdust piles under trim. OSU's fact sheet says the main nest is in damp, decayed wood, so carpenter ants usually point to a leak. Finding the nest is the hard part. See ant control.

Mice

One mouse in October is a trapping job. Droppings in more than one room, or mice that keep coming after a couple of weeks of trapping, is when I would call. Columbus Public Health's rat program treats outdoor areas only and points residents with rats indoors to the property owner or a licensed exterminator. See rodent control.

We only refer companies that hold an Ohio Department of Agriculture pesticide business license and send licensed commercial applicators. To have one look at what you have, ask for a free inspection and a written price before any treatment.