# American cockroach

*Periplaneta americana*

**Identification confidence:** Identifiable with care — Size alone nearly settles it; the pale pronotal margin confirms.

## How to recognise it

- Very large at 34 to 53 mm, the largest cockroach commonly found in US homes.
- Reddish-brown overall with a pale yellowish band forming a rough figure-eight or margin pattern around the edge of the pronotum.
- Adults of both sexes have fully developed wings and can glide, particularly in warm conditions.
- Nymphs are uniformly reddish-brown and lack the German cockroach's pale dorsal stripe.

## What it leaves behind

- Individual large insects appearing at night in bathrooms, kitchens, and basements, often near a floor drain.
- Droppings roughly 2 mm long, blunt-ended and ridged along the sides, larger and more cylindrical than mouse droppings.
- Dark, irregular egg cases about 8 mm glued to surfaces in damp areas.

## Why an infestation persists

Despite the name this is primarily an outdoor and sewer-associated insect in most of the country, entering buildings through drains, sump pits, and gaps at grade. That distinction matters: sightings usually indicate an entry route and a moisture condition rather than an established indoor breeding population, which is the opposite of what a German cockroach sighting means. In Gulf Coast states they also live outdoors in palms and leaf litter, which is where the name "palmetto bug" comes from.


## Where it occurs

Throughout the United States, most abundant in the Southeast and in Gulf Coast states; strongly associated with sewers, steam tunnels, and moist basements.

## What prevents it

- Fit and maintain drain covers, and keep floor-drain and sump traps filled so the sewer route is closed.
- Seal gaps at grade level, around utility penetrations, and beneath exterior doors.
- Correct basement and crawl space moisture, which is what makes the interior habitable.
- Clear leaf litter, mulch, and debris away from the foundation.

## Commonly confused with

- **Oriental cockroach** (*Blatta orientalis*) — Very dark, almost glossy black to deep reddish-brown, noticeably darker than any other common house cockroach.
- **Smoky brown cockroach** (*Periplaneta fuliginosa*) — Uniform dark mahogany to near-black with a glossy sheen, and — importantly — no pale margin on the pronotum, which separates it from the American cockroach.
- **German cockroach** (*Blattella germanica*) — Two dark parallel stripes run front to back on the pronotum, the shield-like plate behind the head. This is the single decisive feature.

**Verdict:** prevention-first. Sightings usually mean an entry route from outdoors or a drain rather than an indoor population. Closing the route and correcting moisture resolves most American cockroach complaints without any treatment.


Source: https://againstpest.shop/identify/cockroaches/american-cockroach/