From an ecological stand point cockroach can be classify into tree distinct groups including domestic, peridomestic and feral. Domestic species of cockroach that live exclusively indoors with human beings. They rely almost exclusively on humans to survive.
They attack stored food and scavenge on any organic material they come across. They are typically active during night time while they prefer to hide during the day typically in bathrooms, kitchen and under sinks. This is typically the case of German and broadbanded cockroaches. Other cockroaches that live around human habitation are known as peridomestic.
They do not require the presence of human for their survival but can exploit any food source that is within their reach. Most species in the genus Periplaneta are peridomestic. The American, Australian and oriental cockroach are all peridomestic.
Their pest status can vary depending on the geographical location. Feral species live exclusively in the wild and account for about 95% of the world cockroach species (reference). There may be some feral species that can invade human habitations but are usually unable to establish themselves indoors.
Cockroaches have a high reproductive rate and thus may quickly invade and colonize houses and workplaces. They are paurometabolous insects, which means that they incomplete metamorphosis with nymphs and adults similar in shape and only differ in size.
Nymphs also lack wings in most species of cockroaches. The number of nymphal instars is typically from 5 to 13 but this number vary among species. Food availability may also dictate the number of instars that nymphal stage may undergo (reference).
The life history of cockroach depends on the species and environmental conditions. The longevity of cockroach vary depending on the species and food availability. It is generally from few weeks to a year (reference). Most peridomestic cockroach species prefer to live in areas with high moisture content. For instance, the oriental and American cockroaches are often found in kitchens, and bedrooms (reference).
Most cockroach species are feral, but few of them have adapted to peri-domestic life. Cockroaches have great reproduction capacity when environmental conditions are favorable. Mating is generally facilitated by sex pheromone emitted by females.