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American Cockroaches: The Big Reddish-Brown “Palmetto Bug”
The American cockroach is the largest common house roach — reddish-brown, up to two inches, and able to fly. Here’s how to identify it and why it shows up in Fresno homes.
American cockroaches are the largest common house cockroach — about 1.5 to 2 inches long, reddish-brown, with a pale yellowish figure-8 marking just behind the head. Despite the name they are not native; they live in sewers, drains, and damp basements, can glide short distances, and are the roach most people mean when they say “palmetto bug” or “water bug.”
If you found a big reddish-brown roach near a drain, in the garage, or scuttling across the bathroom floor at night, it is almost certainly an American cockroach. Unlike the German cockroach, it does not usually breed indoors in large numbers — it comes in from sewers, drains, and the yard, so the fix is as much about entry points and moisture as it is about treatment.
An American cockroach — the largest common house roach, with a yellowish figure-8 marking behind the head.
What an American cockroach looks like
At up to two inches, this is the giant of the common house roaches. It is glossy reddish-brown to mahogany, with a distinctive pale yellow figure-8 or halo pattern on the shield behind the head. Both sexes have full wings. Its size alone separates it from the small German cockroach; you can compare all the species on our California cockroach types guide.
Where American cockroaches come from
American cockroaches thrive in warm, damp, dark places: sewers, storm drains, grease traps, basements, crawlspaces, and the plumbing of older buildings. They commonly enter through floor drains, around pipe penetrations, and under exterior doors. In Fresno they turn up in commercial kitchens, restrooms, and homes with older plumbing, especially when summer heat drives them indoors toward moisture.
Can American cockroaches fly?
Sort of. American cockroaches have full wings and can glide — typically from a higher spot downward — and will make short, clumsy flights in warm conditions, but they are not strong, sustained fliers. Most of the time you will see them running. The ability to glide is one more way to tell this big roach from the German cockroach, which does not fly.
“Palmetto bug” and “water bug” — same insect?
Mostly, yes. “Palmetto bug” is a regional nickname — common in the South — for large cockroaches, usually the American cockroach. “Water bug” is another nickname people use for the American and Oriental roaches because they are found near moisture, even though a true water bug is a different, aquatic insect. We sort out both names here: cockroach vs palmetto bug and cockroach vs water bug.
American vs German vs Oriental — telling the big ones apart
The American cockroach is large and reddish-brown; the German cockroach is small and tan; and the Oriental cockroach is about an inch long and shiny near-black. If it is big and reddish, it is American. If it is small and infesting your kitchen, it is German. If it is dark and showing up in a damp basement or drain, it is Oriental.
Why they enter Fresno homes — and how to keep them out
Because they come from outside and from the plumbing, the most effective steps are exclusion and moisture control: cap unused floor drains, seal gaps around pipes and under doors, fix leaks, and keep crawlspaces dry. Where they keep coming back, a professional treats the entry routes and harborage. Start with our how to get rid of cockroaches in Fresno guide.
See our cockroach control →American cockroach FAQ
Is a palmetto bug the same as an American cockroach?
Usually, yes. “Palmetto bug” is a nickname — mostly used in the South — for large cockroaches, most often the American cockroach. It is not a separate species; it is the same big reddish-brown roach by another name.
Why do I suddenly have American cockroaches?
They typically come in from sewers, drains, the yard, or crawlspaces rather than breeding indoors, so a sudden appearance often follows heat, rain, plumbing work, or a dried-out floor drain. Sealing entry points and fixing moisture problems usually matters more than how clean the home is.
Do American cockroaches fly?
They can glide and make short, clumsy flights using their full wings, especially in warm weather, but they are not strong fliers and mostly run. That gliding ability helps distinguish them from the smaller German cockroach, which does not fly.
Are American cockroaches dangerous?
They do not bite or sting, but because they travel through sewers and drains they can carry bacteria onto surfaces and food, and their droppings and shed skins can trigger allergies and asthma. The main concern is contamination, which is why you do not want them established indoors.
Big roaches coming in from drains or the yard?
Call (559) 472-8200 or request a no-cost inspection — we find the entry points and moisture drawing them in, and treat the source.