Reviewed by William "Willy" Vizcarrondo, NYS DEC Certified Commercial Pesticide Applicator C1825832. Updated September 23, 2026.
Short answer
Size and color tell you. A German cockroach is about 1/2 inch, light brown, with two dark stripes on the shield behind the head, and lives in kitchens and bathrooms. An American cockroach is about 2 inches, reddish brown with a light edge on the shield, and comes from sewers and damp basements. An Oriental cockroach is about 1.25 inches and nearly black, slow, and lives in cool, damp places.
The small one in the kitchen, and the one that's an infestation. UC IPM lists it at about 0.5 inch, light brown, with two dark stripes on the pronotum, the shield behind the head, and UF IFAS puts adults at 1/2 to 5/8 inch with wings, nymphs smaller and wingless. You find them in kitchens, bathrooms and anywhere food is prepared, hidden by day in cracks near food and water. UF IFAS notes they don't come in from outdoors at all; they arrive with people and their things, and they reproduce faster than any other roach, with 3 to 6 generations a year and 30 to 40 nymphs per egg case. If it's small, brown, striped and in the kitchen, it's this one, and it needs a real treatment.
The big reddish one, often called a water bug or palmetto bug. UC IPM describes it at about 2 inches, reddish brown, with a large body and light-colored edges on the pronotum, preferring warm, humid places, and invading sewers and ground floors through damaged pipes. On Long Island it turns up in basements, boiler rooms, garages and around floor drains, especially in summer, and in commercial kitchens and restaurants. One or two in a basement is usually a plumbing or entry problem more than a breeding population in the house.
The dark, slow one in the damp basement. UC IPM lists it at about 1.25 inches, almost black, with the male's wings shorter than its body and the female's wings not fully formed, living outdoors in cool, damp places such as garages, basements and water meter boxes. It can't climb smooth surfaces and it's slower than the others, so you'll see it on the basement floor, under a slop sink, in a crawlspace or coming in under a garage door after rain. It needs moisture, so the fix leans on drying the space and sealing the entry.
German cockroaches are the kitchen problem in Hempstead, Freeport, Long Beach, Valley Stream and the Queens neighborhoods, and they move between attached houses and apartments along the plumbing. American cockroaches come up in the older basements of Huntington, Babylon and Bay Shore and in restaurant kitchens everywhere. Oriental cockroaches show up in damp crawlspaces and garages on the South Shore after wet weather. If you're not sure, send a photo with something for scale. German cockroach treatment from Bobby Bugs carries a 60-day written guarantee.
Related
On Long Island, usually yes. "Water bug" and "palmetto bug" are what people call the American cockroach, the big reddish-brown one from basements and drains. A true water bug is an aquatic insect that lives in ponds and doesn't come inside.
Look at the antennae and the shape. Cockroaches have long, thin antennae, a flattened oval body, and run fast; beetles have shorter, often clubbed antennae, a hard domed back with a visible seam down the middle, and walk slower. Small dark beetles in a pantry are usually pantry pests, not roaches.
Because they travel between units. German cockroaches spread through shared walls, pipe chases and hallways, and UC IPM notes indoor infestations are a known source of allergens and a risk factor for asthma in children, especially in multi-unit housing. One untreated unit keeps the whole line supplied.
Still not sure? Call (516) 509-6001 and we'll tell you what you're dealing with.