information:classification
As pests

The Blattodea include some thirty species of cockroaches associated with humans; these species are atypical of the thousands of species in the order. Of those thirty species, four are most commonly encountered as pests: the German cockroach (Blattella germanica), American cockroach (Periplaneta americana), oriental cockroach (Blatta orientalis), and brown-banded cockroach (Supella longipalpa).

Pest cockroaches feed on human and pet food and can leave an offensive odor. They can passively transport pathogenic microbes on their body surfaces, particularly in environments such as hospitals. Cockroaches are linked with allergic reactions in humans. One of the proteins that trigger allergic reactions is tropomyosin, which can cause cross-reactive allergy to dust mites and shrimp. These allergens are also linked with asthma. Some species of cockroach can live for up to a month without food, so just because no cockroaches are visible in a home does not mean that they are not there. Approximately 20–48% of homes with no visible sign of cockroaches have detectable cockroach allergens in dust.