American Cockroach Identification & Control

At up to two inches long, the American cockroach is the largest roach commonly found in Illinois — but finding one usually means something different than most people assume.

Quick Identification

• Size: Up to 2 inches long — the largest common cockroach in our area
• Color: Reddish-brown with a yellowish figure-eight pattern on the shield behind the head
• Key Features: Large; capable of short flights; prefers damp lower levels; far less likely than German cockroaches to establish large indoor populations
• Also called: Palmetto bug, water bug — both colloquial and technically incorrect
• Habitat: Basements, crawl spaces, floor drains, sewer connections, utility rooms
• Active Season: Year-round; most visible in warm months
• Risk Level: Moderate — health concerns similar to German cockroaches, but rarely establishes in large numbers indoors

What You Need to Know

The American cockroach is the one that makes people call in a panic. At two inches long and capable of short flights, its appearance is genuinely startling. Despite the name, it isn't native to the Americas — it originated in Africa and arrived via shipping centuries ago.

Here's the part that matters most: American cockroaches rarely establish large breeding populations inside homes. They prefer warm, damp environments — sewer systems, storm drains, crawl spaces, and utility tunnels. Individual roaches usually enter through floor drains with dried-out traps, gaps around sewer connections, or foundation cracks, especially during warm weather or after heavy rain pushes them out of the sewer system.

So finding one or two American cockroaches in your basement is a very different situation from finding German cockroaches in your kitchen. The first usually points to an entry point. The second usually points to an infestation.

What to Do

Start with the plumbing. Floor drains that go unused for long stretches lose the water in their traps, which opens a direct path from the sewer line into your basement. Pouring a cup of water down each rarely-used floor drain every month or two keeps the trap sealed and closes the most common entry route. Have a plumber check for gaps around sewer connections and cleanouts as well.

Sanctuary Pest Control does not provide cockroach treatment services. If you're encountering American cockroaches regularly after addressing drains and entry points, contact a pest control company that handles cockroach work. If you're not certain which species you've found, send us a photo — the distinction changes what you should do next.