Bugs That Look Like Cockroaches but Are Not
The bugs most often mistaken for cockroaches are ground beetles, June beetles, click beetles, field and camel crickets, earwigs, stink bugs and wood cockroaches, and none of them infests a home the way a German cockroach does. The quickest test is the back: a beetle has hard wing covers that meet in a straight line down the middle, while a cockroach has soft, overlapping wings (or none) and a flat shield that hides its head from above. Long, whip-thin antennae and a fast, flattened sprint point to a cockroach. Only one lookalike on this list, the wood cockroach, is actually a roach, and it cannot survive indoors.
Most dark, shiny insects found on a kitchen or basement floor at night are not cockroaches. They are outdoor animals that followed a porch light or crawled under a door, and they will usually die or leave within days. This guide covers the lookalikes; for the five real pest roaches drawn to one scale, see our cockroach identification guide.
The lookalikes at a glance
| Insect | Adult size | The giveaway | Breeds indoors? |
|---|---|---|---|
| Ground beetle | About 16 mm for a common species; large ones 25 to 35 mm | Hard, ridged wing covers meeting in a straight seam; head visible, narrower than the thorax | No |
| June beetle (May beetle) | 13 to 25 mm (half an inch to an inch) | Stout, rounded, tan to reddish brown; buzzes and thumps into screens | No |
| Click beetle | Most are small; eyed click beetle 24 to 45 mm | Long, narrow body; snaps and flips into the air when on its back | No |
| Field cricket | 13 to 33 mm | Robust and black, big jumping hind legs, chirps | Seldom |
| Camel cricket | 13 to 33 mm | Humpbacked, wingless, very long antennae and hind legs, silent | Lives in damp basements and crawl spaces |
| Earwig | About 19 mm (three quarters of an inch) | Forceps at the tail end; short wing covers | No |
| Brown marmorated stink bug | About 17 mm | Shield-shaped, banded antennae, smells when handled | No |
| Wood cockroach | Females 19 mm, males up to 25 mm | A real cockroach, often with pale cream edges on the wings and shield | No |
Every insect in the table is a seasonal wanderer or a basement dweller tied to damp, and the fix for each is exclusion, lighting and moisture, not a treatment programme.
The three-second test
Three features separate a cockroach from almost everything that gets confused with one. You can usually check all three without picking the insect up.
- Look at the wings. University of Kentucky entomologists put the rule simply: beetles have hardened front wings, while roaches either have leathery wings or no wings. On a beetle the two wing covers meet in a straight line down the centre of the back; UC IPM notes that adult cockroaches lack these thick, hardened forewings.
- Look for the head. A cockroach has a broad, flattened shield behind the head, the pronotum, and Kentucky notes that roaches have a hood that conceals the head from above. On a ground beetle the head is clearly visible, narrower than the thorax, and projects forward with obvious jaws.
- Look at the antennae and the run. Kentucky describes cockroaches as flattened, brownish, fast-running insects with long, slender antennae, and UC IPM notes their tendency to scatter when disturbed. A ground beetle’s antennae are threadlike, and the beetles below are mostly rounder or more domed than a roach.
One complication: young cockroaches, called nymphs, are smaller and lack wings. A wingless, flat, fast insect with long antennae under the sink is more likely a cockroach nymph than a beetle.
Beetles that look like cockroaches
Ground beetles
North America has more than 2,200 species of ground beetle, and Kentucky notes they may be confused with the Oriental cockroach, since both are shiny and very dark. Ohio State describes ridged wing covers meeting in a straight line, long legs, large eyes and strong jaws, and says they run rapidly, mostly at night.
Sizes vary widely by species. The common Pennsylvania ground beetle is about 16 mm (five eighths of an inch), and the large caterpillar hunters reach 1 to 1 3/8 inches (roughly 25 to 35 mm). Some are drawn to lights and crawl in through gaps, but Ohio State is clear that they do not establish themselves indoors.
They are predators of caterpillars, slugs and soil insects, so sweep up the odd one and put it outside. Our guide to ground and larder beetles covers them in more depth, including the larder beetle, which does mean something is going on indoors.
June beetles and May beetles
These are the stout, reddish brown beetles that thump into window screens on summer nights, and they are the usual answer to “brown bugs that look like roaches”. The University of Maine describes them as stout-bodied, half an inch to an inch or more long, ranging from light tan to reddish brown or even black. Adults emerge in May and June, are nocturnal, and are readily attracted to lights. Their rounded, domed shape is the quickest tell against a flat cockroach.
The adults do little harm. Their larvae are C-shaped white grubs that feed on grass roots in the soil, so they are a lawn issue rather than a house issue.
Click beetles
The University of Maine describes most click beetles as rather small and dull in colour. The name comes from the snap they make: turned on its back, a click beetle rights itself with a sudden click, a mechanism Maine says is used both to startle predators and to get back on its feet. That behaviour is diagnostic on its own. Maine also notes that in hot weather click beetles often come into houses at night through open windows and doors, drawn by lights.
Most are small; the eyed click beetle, with two large false eyes on the shield behind its head, is the exception at 24 to 45 mm, according to UF/IFAS.
Crickets, earwigs and stink bugs
Field crickets and camel crickets
Crickets get mistaken for roaches mainly in basements, where both turn up in the dark. The difference is in the back legs: crickets have large jumping hind legs and leap when disturbed, while cockroaches run. University of Maryland Extension describes field crickets as robust black insects 13 to 33 mm long, usually found on lower floors and in basements. House and field crickets sing; camel crickets do not.
Camel crickets, also called cave crickets, are the ones that look most alarming. Maryland gives them the same 13 to 33 mm range, light tan to dark brown, with extremely long antennae and rear legs. Iowa State adds that they are humpbacked and wingless. Their need for dark, moist places almost always restricts them to damp basements and crawl spaces, so drying the space matters more than any product. Our guide to house and camel crickets covers control.
Earwigs
Earwigs are reddish brown and about three quarters of an inch long, according to UC IPM, and the forceps at the tail end settle the question immediately. They have wings folded under short, hard wing covers but seldom fly. They feed at night and hide by day in dark, cool, moist places, which is why they tend to turn up in damp corners rather than dry rooms. UC IPM advises sweeping or vacuuming them up indoors and sealing the gaps they use, and notes that indoor pesticide use will not prevent them coming in. More in our earwig guide.
Stink bugs
The brown marmorated stink bug is about 17 mm long, mottled brown and, as Penn State describes it, shield-shaped, with lighter bands on the antennae. Penn State is explicit that it will not reproduce inside structures or cause damage. Adults look for overwintering sites from September through October. Our guide to stink bugs and other fall invaders explains why late summer exclusion is the fix.
Wood cockroaches: the real roach that does not infest
Here the lookalike is a genuine cockroach, and the reassuring news is that it is not a pest roach. Penn State Extension describes wood cockroaches as shades of light brown to nearly black, some with cream-coloured stripes on the edges of the wings and the shield behind the head. Males grow up to 1 inch (25 mm) with long wings covering the abdomen; females reach about three quarters of an inch (19 mm) with short, non-functional wings.
They live outdoors in damp leaf litter, under logs and loose bark, in woodpiles and under stones. They come in by accident, through gaps in the foundation or around doors and windows, on firewood, or because males flying at night were drawn to a porch light. Penn State is direct: wood cockroaches do not feed or reproduce indoors, and they die within a few days from dehydration. The University of Kentucky agrees that they cannot survive indoors, though they can be an annoyance in spring and summer when numbers wander in.
The practical advice follows from that. Penn State states that pesticides are not necessary or recommended, and that the best control is keeping them out: sealing cracks in the foundation and gaps around doors and windows, and checking firewood before it comes indoors.
Water bug or cockroach?
“Water bug” means two different things. In everyday speech it usually means a large cockroach. UC IPM notes that the Oriental cockroach, an almost black roach of about 1.25 inches (32 mm), is sometimes referred to as a water bug or black beetle. It lives in cool, damp places such as basements and drains and usually stays on the ground floor. That is a real cockroach, and a moisture problem as much as an insect one.
A true water bug is something else entirely. The giant water bug is an aquatic insect, not a cockroach, and at 2 to 4 inches long it is the largest true bug in the US and Canada, according to the University of Maine. Its other common names include water roach, toe-biter, because it can inflict a painful bite, and electric-light bug, because adults fly to lights at night and end up in parking lots and on porches. One found under a lit doorway in summer has usually flown in from nearby water. Our guide to palmetto bugs, water bugs and croton bugs untangles the names properly.
When it really is a cockroach
If the insect has a flat body, a hood over the head, soft or no wings and long antennae, the next question is which species. A single large roach in summer is usually an outdoor species that wandered in.
The one to take seriously is the German cockroach. It is small, about 13 to 16 mm, light brown with two dark stripes on the shield behind the head. UC IPM says it prefers kitchens, bathrooms and food preparation areas, favouring warm, humid spots close to food, water and dark harbourage, and that it lives and breeds indoors. Adults can hide in a crack a sixteenth of an inch wide, and a single female and her offspring can produce over 30,000 individuals in a year. Signs that point to German cockroaches rather than a wanderer:
- Several small roaches, including wingless nymphs, seen together or night after night.
- Sightings concentrated in the kitchen or bathroom, behind appliances and around sinks.
UC IPM’s guidance is that pesticides alone will not solve cockroach problems, that baits give better control than sprays, and that foggers and bug bombs should be avoided because they can scatter roaches without killing them. An established German cockroach population in most homes is a job for a licensed professional working with baits, sanitation and follow-up visits. Our guide to German cockroach treatment explains why, and cockroach bait versus spray covers the evidence on what works.
How we checked this
Identification features and sizes come from the university extension publications listed under Sources; where they give inches we have converted to millimetres. We left longhorned beetles off this list because we could not find an extension source describing them as a common indoor cockroach lookalike.
Frequently asked questions
What bug looks like a cockroach but is not?
Ground beetles are the most common, followed by June beetles, click beetles, field and camel crickets, earwigs and stink bugs. All of them are outdoor insects that wander in, usually drawn by lights or seeking moisture, and none breeds in a house. Check the back: beetles have hard wing covers meeting in a straight line, while cockroaches have soft overlapping wings or none, and a shield over the head.
How do I tell a beetle from a cockroach?
Look down on it. A beetle has hardened front wings that meet in a straight seam along the middle of the back, and its head is usually visible. A cockroach has leathery, overlapping wings or none, a flat shield over the head, and long, slender antennae. Cockroaches are also flatter and tend to sprint for a crack when the light goes on.
What are the brown bugs that look like roaches in summer?
Most often June beetles, which are stout, rounded and light tan to reddish brown, half an inch to an inch long, and fly to porch lights from May onward. Wood cockroaches are another candidate: they are true roaches, light brown to nearly black, but they live outdoors, die within a few days indoors and do not breed inside. Neither needs a pesticide treatment.
Is a water bug the same as a cockroach?
Usually, in everyday speech. Many people call large dark cockroaches, particularly the Oriental cockroach, water bugs. True giant water bugs are a different insect: aquatic, 2 to 4 inches long, and able to give a painful bite, which is why they are nicknamed toe-biters. They fly to lights at night in summer, so one on a porch has usually come from nearby water.
Do wood cockroaches infest houses?
No. Penn State Extension states that wood cockroaches do not feed or reproduce indoors and die within a few days from dehydration. They arrive on firewood, through gaps, or because males fly to porch lights. Penn State says pesticides are not necessary or recommended, and that keeping them out of the building in the first place is the best control.
Sources
- University of Kentucky Entomology, ENTFACT-706: Ground Beetles, Stephanie Bailey, revised 2026.
- University of Kentucky Entomology, ENTFACT-614: Cockroach Elimination in Homes and Apartments.
- Ohio State University Extension, Fact Sheet HYG-2102: Ground Beetles, David J. Shetlar, 2011.
- University of California Statewide IPM Program, Pest Notes: Cockroaches (Publication 7467).
- University of California Statewide IPM Program, Pest Notes: Earwigs (Publication 74102).
- Penn State Extension, Wood Cockroaches, Michael Skvarla, updated January 2026.
- Penn State Extension, Brown Marmorated Stink Bug, Michael Skvarla.
- University of Maine Cooperative Extension, Home and Garden IPM: May/June Beetles; Click Beetles; Giant Water Bug.
- University of Maryland Extension, Crickets, 2023.
- Iowa State University Extension and Outreach, Yard and Garden: Camel Crickets.
- UF/IFAS Featured Creatures EENY-085: Click Beetles, Alaus spp., R. E. Woodruff.
