Most cockroaches in the U.S. live outside, but some prefer to reside indoors, where they reproduce quickly.

So how do you tell the difference between the occasional cockroach invader and a serious roach infestation?

By knowing the main differences between the most common types of roaches.

Two large, brown cockroaches, one on the bottom corner of the dishwasher and the other eating crumbs off the floor.

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Common House Cockroaches

Roaches are one of the most common house pests.

They are not only a nuisance, but dealing with an infestation can quickly become overwhelming.

However, understanding these insects can help you better control their presence in your home.

A golden colored german cockroach adult with two distinct, dark stripes behind its head and a slightly smaller german cockroach nymph with darker coloring.

A german cockroach adult (right) and nymphs (center and left).Dzurag / Getty Images

Once roaches become settled inside, they are notoriously difficult to eliminate, so prevention is key.

They do best when the temperature is around 70F, but they can reproduce year-round inside.

If you’re sure they’re German cockroaches and see them frequently, seek professional help.

A young, brown-banded cockroach with distinct dark and light coloring and long antennae.

A brown-banded cockroach nymph.G A Chandio / Getty Images

DIY cockroach control can worsen infestations over time, and German cockroaches are especially prone to infestation.

If you’re concerned about oriental cockroaches, address any moisture issues, including leaks and damage from moisture.

They especially like hanging around plumbing and pipes.

A shiny, black oriental cockroach with a hard shell, distinct ovular body, and long, reddish antennae.

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These warm-weather pests require heat and humidity for survival and ideal breeding conditions.

It’s important to know other common roach look-alikes.

They are probably pantry pests if you spot them in your rice, flour, or kitchen cabinets.

A large, oblong, reddish-brown American cockroach with long antennae and spiny red-gold legs.

ViniSouza128 / Getty Images

The German cockroach is the most common roach that infests homes (and apartments).

Unfortunately, German roaches are a common problem worldwide.

DIY cockroach treatments often make themharder to get rid of.

A dark, smoky brown cockroach and smaller, reddish nymph stuck on an insect trap.

An adult smoky brown cockroach (right) and nymph (left).Yusuke Ide / Getty Images Plus

It’s best to contact a local pest pro for further help with indoor roaches.

It’s important to shift the focus from ‘killing instantly’ to ‘killing effectively’.

The roaches didn’t infest overnight and won’t go away overnight.

An Australian cockroach with distinct, light tan head and dark markings, long, dark body, and spiny red-brown legs.

jonesmarc / Getty Images

While it can be frustrating, long-term roach control is all about patience and persistence usingroach trapsand other methods.

Roaches carry diseases and bacteria that spread illness, and severe infestations can cause allergies and asthma issues.

The problems only worsen as time passes, so address roach concerns promptly.

A large, shiny black Florida Woods cockroach with long straight antennae

Chase D’animulls / Getty Images

Donkor, E. S. (2020).Cockroaches and Food-borne Pathogens.Environmental Health Insights,14.

https://doi.org/10.1177/1178630220913365

Brown-banded cockroaches.University of Florida.

A yellow-gold Turkestan cockroach with light colored legs, long antennae, and distinct black eyes.

A male turkestan cockroach.Antagin / Getty Images