Crawling Pests
What Is This Crawling Bug in My House?
By the Clark Pest Entomology Team
Last updated: October 28, 2026
Quick answer: Start with where you found it. Bugs in the kitchen or bath are often roaches or silverfish. Winged insects near wood may be ants or termites. Bugs in damp mulch or under pots are often pillbugs or earwigs. Pick the closest match below, then open that guide for the full look-alike check.
What Did You See Crawling?
Ten kinds of crawling pests turn up in homes and yards across California and Northwestern Nevada. Tap the one that looks closest.
Ants
A narrow waist and bent antennae. You may see trails in the kitchen, mounds in the yard or ants coming out of wood.
Termites
A thick waist, straight antennae and wings of equal length. Winged ones near a window are the usual alarm.
Cockroaches
A flat, oval body with long antennae. Size and color tell German, brown banded, oriental and American roaches apart.
Beetles
Carpet beetles eat wool and fur. Weevils and flour beetles get into pantry goods. Powderpost beetles tunnel into wood.
Silverfish and Firebrats
Slender, wingless and shiny, with three tail-like parts. They look alike, so check the room. Silverfish like damp. Firebrats like hot and dry.
Earwigs
About 1/4 to 1 inch long with pincers on the tail. They hide in moist, shady spots by day and wander in by mistake.
Pillbugs
Gray and dome-shaped, and they roll into a ball. They are harmless crustaceans from under pots and damp mulch.
Spiders
Most are harmless hunters that eat insects. Legs, body shape and web tell you which few need real attention.
Ticks
Small blood-feeding arachnids, not insects. They rarely settle in a house unless they ride in on a pet.
True Bugs
Insects with a beak made for sucking sap or blood. The bed bug is the one most people mean.
Look-Alikes: Four Quick Tests
These pairs get mixed up the most. Each one has a single clue that settles it.
| Often mixed up | The quick test | Why it matters |
|---|
| Flying ant or termite | Look at the waist, antennae and wings. Ants have a narrow waist, bent antennae and back wings shorter than the front ones. Termites have a thick waist, straight antennae and wings of equal length. | Termites can damage the wood in a home, so this is the test not to guess on |
|---|
| Cockroach or beetle | A cockroach has a flat body and long antennae. Adult roaches have thin, papery wings. Beetles have thick, hard wing covers. | Roaches thrive where they find food, water and shelter. Beetles are tied to what they feed on, such as fabric, pantry goods or wood |
|---|
| Pillbug or sowbug | Pillbugs roll into a tight ball. Sowbugs cannot, and they have two small tail projections. | Both are harmless, and both point to damp ground near the house |
|---|
| Silverfish or firebrat | They look almost the same. Silverfish want damp rooms. Firebrats want hot, dry ones. | The room you found it in tells you what to fix |
|---|
Where You Found It Tells You What It Is
Kitchen, bathroom or under the sink
Small bugs near water and food point to cockroaches or silverfish. German roaches breed indoors and spread fast. Silverfish settle in damp rooms. Fix leaks and wipe up moisture before anything else.
Windowsills, walls and wood
Winged insects crowding a windowsill cause the most worry. Check the waist before you panic. If the waist is thick and the wings match, open the Termites guide above. If the waist is narrow, it is an ant, and the Ants guide above will help you name it.
Yard, mulch, flower pots and door thresholds
Pillbugs and earwigs live in moist, shady places. They wander indoors by accident. Both die quickly indoors. Sealing door gaps and drying out the ground beside the house is often enough.
Bedroom, couch or pet bedding
Think bed bugs, carpet beetles or ticks. Ticks ordinarily do not infest a house. They hitch a ride on a pet or a rodent. Carpet beetles feed on wool, fur and other natural fibers. Bed bugs feed on blood. The right guide depends on what you are seeing and where.
Which Crawling Pests Can Hurt You or Your Home?
Most crawling pests are a nuisance. A few carry real risk.
Pests that damage a building
Termites hollow out wood. Carpenter ants tunnel through it to nest. Powderpost beetles tunnel into it too. All three deserve a fast, correct ID.
Pests that affect health
Ticks can carry diseases, including Lyme disease. Cockroach allergens are a risk factor for asthma in children, according to UC IPM. German cockroaches are also believed to carry disease-causing organisms. A small number of spiders are a real medical concern. Our spider guide shows which ones.
Pests that are mostly a nuisance
Earwigs, pillbugs and silverfish do not bite people or wreck a house. Silverfish may damage paper and fabric. The rest are occasional visitors.
What to Do First
Do not spray the first thing you see. Spraying a trail of ants kills the ants you can see while the colony sends more. Baits that workers carry back to the nest work better, and UC IPM says bait control can take more than a week. See the UC IPM ant guide for how to match a bait to your ant.
For roaches, skip the bug bomb. UC IPM warns that foggers often miss the cracks where roaches hide and can scatter them into other rooms. The UC IPM cockroach guide covers monitoring, baits and sealing.
Whatever you find, fix leaks, drips and sprinklers that hit the foundation, and seal gaps around doors and pipes.
Clark's Expert Insight
Check the water first. Earwigs and pillbugs wander in looking for moisture, and silverfish settle in damp rooms. Dry out the spot and many of these visitors stop coming. Termites and German roaches are different. Moisture control helps, but they need a plan built for that species.
Crawling Pest Questions Homeowners Ask
How can I tell a flying ant from a termite?
Look at the waist, antennae and wings. Ants have a narrow waist, bent antennae and back wings shorter than the front ones. Termites have a thick waist, straight antennae and wings of equal length.
Are pillbugs and sowbugs the same thing?
No, but they are close cousins and both are harmless. Pillbugs roll into a tight ball. Sowbugs cannot roll up and have two small tail projections.
Do I need to treat for earwigs or pillbugs?
Usually not. Both are occasional invaders that wander in looking for moisture. Reducing moisture and sealing cracks is often enough to keep them out.
Do ticks live in my house?
Ticks ordinarily do not infest a house. They usually get inside by riding on a pet or a rodent.
Which crawling pests are most dangerous?
Ticks can carry diseases like Lyme disease. Cockroaches add allergens linked to asthma in children, and a few spiders are a real medical concern. Termites can cause costly structural damage.
What kills all crawling bugs?
Nothing does. Ants need baits that workers carry back to the colony. Roaches need baits and cleanup, not bug bombs. Naming the pest first is what makes the treatment work.