American Cockroach

Periplaneta americana

American Cockroach

Periplaneta americana

Take care

Handle with care

It does not meaningfully bite. It matters because it moves between drains, sewers and kitchen surfaces, and because cockroach allergens are a recognised asthma trigger. The animal itself is not attacking you.

We identify, we don't diagnose. If you've been bitten or stung and symptoms develop, or you're worried, seek medical attention.

Size35–50 mm

MarkingsLarge — 35–50 mm, the biggest cockroach most Americans will see indoors · Glossy reddish-brown with a pale yellowish figure-of-eight behind the head

WhereSewers, drains, steam tunnels, basements and crawl spaces. Comes up into buildings rather than living in the kitchen cabinetry.

How to tell it apart

Large — 35–50 mm, the biggest cockroach most Americans will see indoors
Glossy reddish-brown with a pale yellowish figure-of-eight behind the head
Fully winged, and it does fly, usually downwards from a height
Very long antennae, often as long as the body
Turns up singly at night, usually near a drain, basement or bathroom

Where you’ll find it

Across the United States, most abundant in the south and in cities with extensive sewer networks.

Sewers, drains, steam tunnels, basements and crawl spaces. Comes up into buildings rather than living in the kitchen cabinetry.

How it behaves

Despite the name it is not native to America — it arrived from Africa centuries ago. The important behavioural point is that it commutes: it lives in drains, sewers and warm service voids and comes up at night, so a single large roach in a bathroom usually means a route in rather than a resident population. It is among the fastest land invertebrates relative to its size, and it can run on two legs at speed. Flight is more of a controlled glide, and it happens most in warm weather.

You’ve found one indoors

Look for the route rather than the roach. Floor drains that have dried out, gaps around soil pipes, and unsealed basement penetrations are the usual entries — keeping traps filled with water and sealing pipe collars does more than spraying. Repeated sightings in numbers, rather than the occasional large wanderer, are worth professional attention.

Common questions

Is a palmetto bug the same thing?

Usually yes. In the southern US 'palmetto bug' most often means this species, occasionally a smoky brown cockroach. It is a nicer name for the same animal.

Does one in the bathroom mean an infestation?

Often not. This species lives in drains and sewers and comes up. One at night near a drain points at a route in; several, or nymphs, points at something breeding on site.

Can they fly?

Yes, though it is closer to a glide and they mostly do it going downwards or in warm weather. It is startling and harmless.

Do they bite people?

Essentially never. Documented bites are extremely rare and associated with heavy infestations. The health concern is allergens and contamination, not biting.

Commonly confused with

Oriental Cockroach Take care
Madagascar Hissing Cockroach Harmless

Keep identifying

Identify another animal from a photo or return to the Cockroaches guide.

Previous: Brown-banded Cockroach · Next: Oriental Cockroach

Where this was checked

iNaturalist — Periplaneta americana checked 2026-07-30

Last reviewed 2026-07-30. We identify, we don’t diagnose — what we can and can’t tell you.