Bug Identifier
Identification

Bugs in the Bathroom: 11 Types and What to Do

By the Bug Identifier Editorial Team. Updated September 27, 2026. 4 minute read.

Bugs in the Bathroom are one of the most common identification questions we get. Here are 11 you are likely to see.

How to narrow it down

Narrow it down with three quick checks. Count the legs: insects have six, spiders and ticks have eight, and centipedes and millipedes have many more. Check for wings, even folded ones. Then compare size against a coin: a US penny is 19 mm across. Our bug identifier tool does this filtering for you.

The 11 bugs

American Cockroach

American CockroachPeriplaneta americana35–53 mmNuisance

The largest common house cockroach, a reddish-brown roach that lives in sewers, basements and steam tunnels. It can fly short distances in warm weather.

Tell-tale sign: Large reddish-brown body up to two inches long. Risk: American cockroaches can spread bacteria to food and trigger allergies and asthma.

Drain Fly

Drain FlyClogmia albipunctata2–5 mmNuisance

A small, fuzzy, moth-like fly that rests on bathroom walls near sinks, tubs and floor drains. Its larvae live in the slimy film inside drains.

Tell-tale sign: Fuzzy, gray, leaf-shaped wings held roof-like over the body. Risk: Drain flies don't bite and aren't known to spread disease in homes.

Earwig

EarwigForficula auricularia12–20 mmNuisance

A slender, reddish-brown insect with a pair of pincers on its tail. Earwigs hide under mulch and pots by day and chew seedlings, flowers and soft fruit at night.

Tell-tale sign: Forceps-like pincers at the end of the abdomen. Risk: Earwigs can pinch but are harmless, and they do not crawl into ears.

German Cockroach

German CockroachBlattella germanica12–15 mmNuisance

A small, light-brown cockroach that breeds rapidly in kitchens and bathrooms, especially in apartments and restaurants. Females carry their egg case until it is ready to hatch.

Tell-tale sign: Light tan to brown body about half an inch long. Risk: German cockroaches contaminate food, and their droppings and shed skins are a major asthma trigger.

House Centipede

House CentipedeScutigera coleoptrata25–35 mmNuisance

A fast, yellowish-gray centipede with 15 pairs of very long legs that races across floors and walls at night. It hunts silverfish, cockroaches and spiders.

Tell-tale sign: Fifteen pairs of long, banded legs. Risk: House centipedes rarely bite; a bite feels like a mild bee sting.

Odorous House Ant

Odorous House AntTapinoma sessile2–3 mmNuisance

A small, dark brown to black ant that trails along counters and sinks looking for sweets. Crushed workers give off a smell often compared to rotten coconut.

Tell-tale sign: Small, uniformly dark ant with an uneven thorax. Risk: Odorous house ants are a nuisance only; they rarely bite and don't sting.

Oriental Cockroach

Oriental CockroachBlatta orientalis25–30 mmNuisance

A shiny, dark brown to black cockroach that prefers cool, damp places such as basements, drains and crawl spaces. Females have tiny wing pads, and neither sex can fly.

Tell-tale sign: Glossy black or very dark brown body. Risk: Oriental cockroaches feed on garbage and sewage and can spread bacteria to surfaces.

Pharaoh Ant

Pharaoh AntMonomorium pharaonis1.5–2 mmNuisance

A tiny, pale yellow ant that nests in warm, hidden spots inside walls, cabinets and appliances. Colonies split into new nests when disturbed, which makes them hard to control.

Tell-tale sign: Very small, light yellow to amber body with a darker abdomen. Risk: They don't bite, but in hospitals and kitchens they can carry bacteria onto clean surfaces.

Silverfish

SilverfishLepisma saccharina12–19 mmNuisance

A wingless, carrot-shaped insect covered in silvery scales that moves with a fish-like wiggle. It eats paper, glue, starches and fabrics in damp areas.

Tell-tale sign: Silvery-gray, teardrop-shaped, scaly body. Risk: Silverfish don't bite; they damage books, wallpaper and stored papers.

Cellar Spider

Cellar SpiderPholcus phalangioides7–10 mmHarmless

A pale, delicate spider with extremely long, thin legs that hangs upside down in loose webs in basements and ceiling corners. When disturbed, it vibrates rapidly in its web.

Tell-tale sign: Tiny, peanut-shaped body with very long, hair-thin legs. Risk: Cellar spiders are harmless to people; the myth that they are deadly but can't bite is false.

Springtail

SpringtailCollembola class1–2 mmHarmless

A tiny, wingless hexapod that jumps using a tail-like spring folded under its body. Springtails swarm in damp soil, potted plants and around leaks.

Tell-tale sign: Pinhead-size gray, white or black body. Risk: Springtails don't bite or damage homes; large numbers usually point to a moisture problem.

Which ones should you worry about?

0 of the 11 bugs in this guide can bite or sting. None of them are considered medically significant. The rest are harmless or simply a nuisance.

Comparison at a glance

American CockroachDrain FlyEarwig
GroupCockroachesFlies & MosquitoesCentipedes, Millipedes & Crawlers
Scientific namePeriplaneta americanaClogmia albipunctataForficula auricularia
Size35–53 mm2–5 mm12–20 mm
ColorsRed and BrownGray and BlackBrown and Red
Legs6 legs6 legs6 legs
WingsYesYesYes
Bites or stingsNoNoNo
RiskNuisanceNuisanceNuisance
Key featureLarge reddish-brown body up to two inches longFuzzy, gray, leaf-shaped wings held roof-like over the bodyForceps-like pincers at the end of the abdomen

Frequently asked questions

What is the most common one?

Among the bugs in this guide, the American cockroach and drain fly are the ones people ask about most.

Which of these are dangerous?

None of them are medically significant, though some can bite or sting.

How can I identify a bug I found?

Use the free bug identifier tool: choose the number of legs, wings, main color, size and where you found it, and it will list the closest matches.