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Bugs in the bathroom

Bathrooms draw bugs that need moisture: silverfish, drain flies, centipedes, sowbugs and the occasional spider stuck in the tub. Most are harmless, and drying the room out does more than any spray.

Found in the bathroom

27 kinds, most dangerous first. Tap one for photos, the danger rating and what to do.

Arizona bark scorpionGet adviceBlacklegged tickGet adviceLone star tickGet adviceAmerican cockroachBe carefulBroad-faced sac spiderBe carefulFalse black widowBe carefulGerman cockroachBe carefulHobo spiderBe carefulHouse centipedeBe carefulNorthern yellow sac spiderBe carefulOriental cockroachBe carefulPharaoh antBe carefulRed imported fire antBe carefulYellow fever mosquitoBe carefulArgentine antHarmlessBarn funnel weaverHarmlessBlack carpenter antHarmlessCamel crickets (native)HarmlessDrain flyHarmlessEuropean earwigHarmlessGiant house spiderHarmlessGreenhouse millipedeHarmlessLong-bodied cellar spiderHarmlessOdorous house antHarmlessPill bugHarmlessSilverfishHarmlessWoodlouse spiderHarmless

Why bugs end up in the bathroom

A bathroom stays damp long after a shower, and many small arthropods dry out quickly in normal indoor air. Silverfish, house centipedes, pill bugs and camel crickets look for that humidity. Drain flies breed in the film that builds up inside sink and shower drains.

A spider in the bathtub usually didn't come up the drain. Spiders wander in, often looking for water, and can't climb back out of the smooth sides.

What you can do today

  • Run the exhaust fan during and after showers, or leave the door open to let the room dry.
  • Scrub drains with a stiff brush and an enzyme drain cleaner if you see tiny fuzzy moth-like flies. Boiling water alone rarely clears the film.
  • Fix leaky faucets, running toilets and soft caulk around the tub. Dry areas under the sink.
  • Seal gaps where pipes enter the wall and around baseboards.
  • Use a cup and a piece of paper to move a spider from the tub outdoors. Most bathroom spiders are harmless.

When it's more than a nuisance

House centipedes can give a mild bite if handled, and sac spiders occasionally bite people at night. In the Southwest, Arizona bark scorpions turn up in bathrooms and can hide in damp towels, and their sting is rated Get advice. Shake out towels and bath mats there before use, and call Poison Help at 1-800-222-1222 right away for any sting.